How do you add these two consecutive triangular numbers?
TR(4)+TR(3)

Answers

Answer 1

The n-th trianglar number is given by

[tex]T_n = \dfrac{n(n+1)}2[/tex]

Then

[tex]T_4 + T_3 = \dfrac{4\times5}2 + \dfrac{3\times4}2 = \boxed{16}[/tex]

Alternatively, the triangular numbers are defined recursively by

[tex]\begin{cases}T_1 = 1 \\ T_n = T_{n-1} + n & \text{for } n>1\end{cases}[/tex]

This means

[tex]T_1=1[/tex]

[tex]T_2 = T_1 + 2 = 3[/tex]

[tex]T_3 = T_2 + 3 = 6[/tex]

[tex]T_4 = T_3 + 4 = 10[/tex]

so that

[tex]T_3+T_4=\boxed{16}[/tex]


Related Questions

A student earned a grade of 70% on a math test that had 20 problems. How many problems on this test did the student answer correctly? ( round to the nearest whole number)

Answers

Answer:

14

Step-by-step explanation:

Given:

A student earned a grade of 70% on a math test that had 20 problems.

To Find:

How many problems on this test did the student answer correctly? ( round to the nearest whole number)

Solve:

When I solve these question I have a formula.

Which is

Number of question correctly ÷ Total × 100

Thus,

1/20 × 100 = 5%

2/20 × 100 = 10%

3/20 × 100 = 15%

4/20 × 100 = 20%

5/20 × 100 = 25%

6/20 × 100 = 30%

7/20 × 100 = 35%

8/20 × 100 = 40%

9/20 × 100 = 45%

10/20 × 100 = 50%

11/20 × 100 = 55%

12/20 × 100 = 60%

13/20 × 100 = 65%

14/20 × 100 = 70%

15/20 × 100 = 75%

16/20 × 100 = 80%

17/20 × 100 = 85%

18/20 × 100 = 90%

19/20 × 100 = 95%

20/20 × 100 = 100%

As you can see that 14/20 × 100 = 70%

Hence, the student answer 14 question correct.

Kavinsky

Dave loves underwater diving. His house boat is 250 feet above sea level. He jumped from that level. He went 600 feet below sea level. How many feet did Dave go under the water?

Answers

Answer:

600 feet

Step-by-step explanation:

I would just like to explain how this works with a visual (please enjoy my drawing <3 haha)

With my drawing we know that the bird is 150 feet above sea level, and the fish is 100 feet below sea level.

From the bird to the water it is 150 feet, from water to fish is 100 feet

From the bird to the fish it is 150 feet + 100 feet

This is equal to 250 feet,

so we know from the bird (150 feet above sea level) to the fish(100 feet below sea level).

Knowing this information we can easily answer this questionDave is 250 feet above sea level, and he went 600 feet nelow sea level, meaning he only went 600 feet under the water.

A home is purchased for $75,000, and remodelled spending $35,000. five years later, the home is sold for $160,000. what is the capital gain/loss, and at what percent of profit/loss?

Answers

Answer:

31.2%

Step-by-step explanation:

75000+35000 = 110000

160000 - 110000 = 50000

50000 ÷ 160000 = 0.312

0.312 x 100 = 31.2 %

Marcy makes 15 of 20 free throws at basketball practice. What is the probability that she will miss her free throw? Possible answers are A. 1/2 B. 3/4 C.2/5. D. 1/4

Answers

Answer:

  D.  1/4

Step-by-step explanation:

You want to know the probability Marcy will miss a free throw, given that she makes 15 of 20.

Probability

We assume Marcy's record at practice is typical of her performance. It tells us that she makes 15/20 = 3/4 of the free throws she takes. That means she misses 1 -3/4 = 1/4 of the free throws.

The probability she will miss her free throw is 1/4.

__

Additional comment

Many assumptions are involved in this calculation. One of them is that her next throw is unaffected by her last throw. It is a rare player for whom that is the case.

<95141404393>

3[(x^3 -7x+1) - (x+4)]
О А. 3х³ - 24х-9
О B. х-8х-3
0 С. 3x²-5x-6
O D. 3x²-6x+15

Answers

Answer:

A

Step-by-step explanation:

You have to simplify the brackets in turn.

3 times x^3- 7x+1 = 3x^3- 21x+ 3

then do 3 times x + 4= 3x + 12

you then add them all together, if they have a power add them, if they just have an x add them, and if they are just a number add them.

So it goes to 3x^3- 24x - 9,

this is because 3x^3 cant be added/ subtracted by anything, -24x is made from -21x- 3x, and -9 is made from 3 - + 12, so this means 3 - 12 = -9.

I hope this helps, have a lovely day.

a bus left town X at 6:30 and arrived at town Y at 1:00pm if the bus travelled 100km per hour calculate the distance from town X and Y​

Answers

650km since 1pm-6:30am equals 6 hours and 30 minutes.

What am I supposed to do? Someone please help I frl will Lu.v 697 forever

Answers

Answer:

From the given diagram m>2 and m>3 are supplementary angles because they sum upto 180 degrees and m<2 and m<4 are vertically opposite angles

(3,7), (1,8)
find the distance between each pair of points ​

Answers

Answer:

[tex]\sqrt{241}[/tex]

Step-by-step explanation:

3+1=4

7+8=15

4^2=16

15^2=225

16+225=241

[tex]\sqrt{241}[/tex]

the distance is (-2,1)

Find the distance between the points given below. Round your answer to the nearest tenth.
A (0,6) and B (-3,-1)

Answers

Answer:

7.6

Step-by-step explanation:

We want to find the distance between (0,6) and (-3,-1)

We can find the distance between any two points using the distance formula

Distance between two points =

[tex] \sqrt{(x2 - x1)^{2} +(y2 - y1) {}^{2} } [/tex]

Where the values of x and y are derived from the the two points. (x1,y1) and (x2,y2)

Here the two points are (0,6) and (-3,-1)

So we have (x1,y1) = (0,6) so x1 = 0 and y1 = 6

And we have (x2,y2) = (-3,1) so x2 = -3 and y2 = -1

Now we plug in the values of x and y into the formula and evaluate to get the distance.

Again recall distance = √(x2-x1)²+(y2-y1)²

==> plug in x2 = -3 , x1 = 0, y2 = -1 and y1 = 6

Distance = √(-3-0)²+(-1-6)

==> evaluate operations inside of parenthesis

Distance = √(-3)²+(-7)²

==> evaluate all exponents

Distance = √9+49

==> and 9 and 49

Distance = √58 = 7.6 (rounded)

explain how its false

Answers

The powers will be added together not the numbers ( bases)

Answer:

  No

Step-by-step explanation:

An exponent signifies the number of times the base is a factor in the product. When products involving the same base are multiplied, the total number of factors is the sum of the number in each of those products.

__

  [tex]5^2=5\cdot5\\\\5^9=5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5\\\\5^2\cdot5^9=(5\cdot5)\cdot(5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5\cdot5)=5^{11}[/tex]

The base of the exponent in the product is the value that is a repeated factor. It is 5, not (5·5).

Your friend is not correct.

__

The general rule for exponents is ...

  (a^b)(a^c) = a^(b+c)

Write the inequality given in the diagram below

Answers

Step-by-step explanation:

it's either 3 or 2 probably

!PLEASE HELP!
Find the length of the missing side. Round your answer to the nearest tenth.

A) 2.8
B) 6.5
C) 4.7
D) 8.2

Answers

Answer: B) 6.5

Step-by-step explanation:

   We will use the Pythagorean theorem to solve. The "c" variable is the hypotenuse and the other variables are the legs.

a² + b² = c²

3.6² + b² = 7.4²

12.96 + b² = 54.76

b² = 41.8

b = [tex]\sqrt{41.8}[/tex]

b ≈ 6.5

     The length of the missing side is about B) 6.5.

Answer:

B)6.5

Step-by-step explanation:

H²=P²+B²

7.4²=3.6²+B²

B=√41.8

B=6.465≈ 6.5

can someone help me Im lost here

Answers

Answer:

  walk area = 125.6 m²

Step-by-step explanation:

You are asked for the area of a sidewalk of given width that is around a circle of given radius. The pattern you're asked to fill in would have you compute the area of the inner circle, and of the outer circle, then find the difference between the areas.

__

The formula for the area of a circle is ...

  A = πr²

bigger circle

The radius is shown as 11 m, so its area is ...

  A = π(11 m)² = 121π m² = 379.94 m²

smaller circle

The radius is shown as 9 m, so its area is ...

  A = π(9 m)² = 81π m² = 254.34 m²

area difference

The difference between the two areas is ...

  walk area = big circle area - small circle area

  walk area = 379.94 m² -254.34 m² = 125.6 m²

_____

Additional comment

The area can also be computed by multiplying the centerline length of the sidewalk by its width. The center of the walk is (9+11)/2 = 10 m from the centers of the circles, so the circumference (centerline length) is

  C = 2πr = 2(3.14)(10 m) = 62.8 m

The width of the sidewalk is 11 -9 = 2 meters, so its area is ...

  (2 m)(62.8 m) = 125.6 m² . . . . sidewalk area

simplify √(x^2-10x+25) if -5≤x<5

Answers

[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]

Let's simplify ~

[tex]\qquad \sf  \dashrightarrow \: \sqrt{ {x}^{2} - 10x + 25 } [/tex]

[tex]\qquad \sf  \dashrightarrow \: \sqrt{ {x}^{2} - 5x - 5x + 25 } [/tex]

[tex]\qquad \sf  \dashrightarrow \: \sqrt{ {x}^{} (x- 5) - 5(x - 5) } [/tex]

[tex]\qquad \sf  \dashrightarrow \: \sqrt{ (x- 5) (x - 5) } [/tex]

[tex]\qquad \sf  \dashrightarrow \: \sqrt{ (x- 5) {}^{2} } [/tex]

[tex]\qquad \sf  \dashrightarrow \: (x- 5) [/tex]

value x lies between :

[tex]\qquad \sf  \dashrightarrow \: - 5 \leqslant x \leqslant 5[/tex]

if the value of x is taken -5

[tex]\qquad \sf  \dashrightarrow \: - 5 - 5[/tex]

[tex]\qquad \sf  \dashrightarrow \: - 10[/tex]

if value of x is taken as 5

[tex]\qquad \sf  \dashrightarrow \:5 - 5[/tex]

[tex]\qquad \sf  \dashrightarrow \:0[/tex]

So, the possible values of the required expression lies between ~

[tex]\qquad \sf  \dashrightarrow \: - 10 \leqslant \sqrt{ {x}^{2} - 10x + 25 } < 0[/tex]

I hope you understood the whole procedure. let me know if you have any doubts in given steps ~

in need of some help <3

If ∆ABC~∆XYZ, area (∆ABC) : the area (∆XYZ) = 4:9, then AB:XY is...

Answers

Answer:

AB : XY = 2 : 3

Step-by-step explanation:

We know that :

area ∝ length²

So, if the areas ΔABC and ΔXYZ are in the ratio 4 : 9, then :

ΔABC : ΔXYZ ∝ AB² : XY²4 : 9 ∝ √4 : √94 : 9 ∝ 2 : 3

Which of the following statements could be translated to the equation n - 5 = -2?

- A number less than five equals negative two.
- The difference between a number and five is negative two.
- If five is subtracted from a number, the result is two.
- Five less a number is equal to two.

Answers

The answer is The difference between a number and five is negative two

Answer:

B.

Step-by-step explanation:

We know that:

n - 5 = -2

We also know:

A number that replaces the n value is less than 5.

Here are the answers verified:

A. False. I don't know if it makes sense.B. Correct. The difference also means subtraction.C. False. I don't know if it makes sense.D. False. I don't know if it makes sense.

The correct option is B.

if a square is drilled out from a cylinder what will be the lateral surface area,total surface area,base area and the volume of the cylinder​

Answers

The cylinder is a three-dimensional shape and it has a radius, diameter and a height

How to determine the lateral surface area?

Assume the square has the following dimensions:

Base dimensions = x

Height = h

Assume the cylinder has the following dimensions:

Radius  = r

Height = h

When the square is drilled out, the lateral surface area would be:

Lateral Area = Cylinder - Square

This gives

[tex]Lateral = 2\pi rh - 4xh[/tex]

Factor out 2h

[tex]Lateral = 2h( \pi h - 2x)[/tex]

How to determine the total surface area?

Using the same dimensions in (a), we have:

Total surface Area = Cylinder - Square

This gives

[tex]Area = 2\pi r(r +h) - 2(2x^2 - xh)[/tex]

Factor out 2

[tex]Area = 2[\pi r(r +h) - (2x^2 - xh)][/tex]

How to determine the base area?

Using the same dimensions in (a), we have:

Base area = Cylinder - Square

So, we have:

[tex]Base = \pi r^2 - x^2[/tex]

How to determine the volume?

Using the same dimensions in (a), we have:

Volume = Cylinder - Square

So, we have:

[tex]Volume = \pi r^2h - x^2h[/tex]

Factor out h

[tex]Volume = h(\pi r^2 - x^2)[/tex]

Read more about cylinder at:

https://brainly.com/question/9554871

#SPJ1

question 6. evaluate the expression

Answers

[tex]|-24 \div 2^2|\\\\\\=\left|-24 \times \dfrac 1{2^2} \right|\\\\\\=\left|-\dfrac{24}4\right|\\ \\\\=|-6|\\\\\\=6[/tex]

-24 divided by 2 will be a negative answer which is -6 cause if you do -21 divided by 2 powered by 2. -6 is your answer I hope that’s right and hope this helps.

Please help! lol and thanks to whoever helps

Answers

[tex]\textit{volume of a rectangular prism}\\\\ V=Lwh ~~ \begin{cases} L=length\\ w=width\\ h=height\\[-0.5em] \hrulefill\\ h=1.8\\ L=4.2\\ V=26.46 \end{cases}\implies \begin{array}{llll} 26.46=(4.2)w(1.8)\implies 26.46=7.56w \\\\\\ \cfrac{26.46}{7.56}=w\implies 3.5=w \end{array}[/tex]

A jar contains 32 red marbles numbered 1 to 32 and 38 blue marbles numbered 1 to 38. A marble is drawn at random from the jar. Find the probability of the given event. Please enter reduced fractions.

(a) The marble is red. P(red)=

(b) The marble is odd-numbered. P(odd)=

(c) The marble is red or odd-numbered. P(red or odd) =

(d) The marble is blue or even-numbered. P(blue or even) =

Answers

Answer:

(b)the marble is odd-numbered.P(odd)=

1



math




math geniuses pls help!!!




pls check other questions as well thanks,!

Answers

Using the given box and whisker plot, it is found that the mean most likely exceeds the median for Elaine, hence option B is correct.

What does a box and whisker plot shows?

A box and whisker plot shows three things:

The 25th percentile, which is the median of the bottom 50%.The median.The 75th percentile, which is the median of the upper 50%.

In this problem:

The plot for Sarah is right-skewed, due to the proximity of the 25th percentile and the median. In a right skewed plot, the mean is less than the median.For Elaine, it is left-skewed, due to the proximity of the median to the 75th percentile. In a left skewed plot, the mean exceeds the median.

The mean most likely exceeds the median for Elaine, hence option B is correct.

More can be learned about box and whisker plots at https://brainly.com/question/27743205

#SPJ1

the dimensions of a rectangle can be represented by the expressions (x+7) and (x-3). if the area of the rectangle is 75 square feet, find the value of x.

Answers

Answer:

Step-by-step explanation:

Area of rectangle is  b*h

so

a = (x-3)(x+7)

75 = (x-3)(x+7)

75 = x²+4x-21

0 = x²+4x-96

(x+12)(x-8)=0

x = -12, or x = 8

5

——
——


i need help!!


————-
math geniuses pls help me!

Answers

Answer:

C

Step-by-step explanation:

  x = 7 cos (2pi/3)            y =  7 sin (2pi/3)

  x = -7/2                          y = 7 sqrt(3) /2

& this one, please and thank you!!

Answers

[tex]\text{Given that,} ~ p(x) = x^2 -5~ \text{and}~ h(x) = \sqrt{x+5}\\\\(p\circ h)(x)\\\\=p(h(x))\\\\=p\left( \sqrt{x+5} \right)\\\\=\left( \sqrt{x+5} \right)^2 -5\\\\=x +5-5\\\\=x[/tex]

How many solutions does the following equation have? 3(2x−4) =2(3x−6)

Answers

Answer:

Infinitely many solutions

Step-by-step explanation:

Equations can either have no solutions, one solution, or infinitely many solutions.

Examples:

No solutions: 2 = 6One solution: x = 2Infinitely many solutions: 2 = 2

Given: 3(2x − 4) = 2(3x − 6)

Distribute:

3(2x − 4) = 2(3x − 6)

3(2x) + 3(−4) = 2(3x) + 2(−6)

6x − 12 = 6x − 12

As both sides of the equation are identical, this equation has an infinite number of solutions.

Learn more here:

https://brainly.com/question/25326244

Write an equation for the line that has a slope of -2/3 and goes through the point (-6,8)

Answers

Answer:

The solution is in the image

Answer:

y = (-2/3)x + 4

Step-by-step explanation:

the equation of a line is given by the formula y = mx + b where m is the slope and b is the y intercept.

so,

y = (-2/3)x + b

to find b we plug in the values of x and y given by the point (-6,8)

8 = 4 + b

b = 4

so y = (-2/3)x + 4

5x + 12= 6x - 36

I’m bored

Answers

Answer:

x = 48

Step-by-step explanation:

5x + 12 = 6x - 36 ( subtract 6x from both sides )

- x + 12 = - 36 ( subtract 12 from both sides )

- x = - 48 ( multiply both sides by - 1 )

x = 48

Step-by-step explanation:

______________________

5x + 12 = 6x - 36

5x + 12 - 6x = - 36

- x = - 36 - 12

- x = - 48

Now change the sign of both side of the equation...

x = - ( - 48)

x = 48...

______________________

W
Which inequality represents this problem?
• Jerry has $30 in his savings account, and he deposits $6 each month.
• Amber has $80 in her savings account, and she does not make any
additional deposits or withdrawals.
After how many months, m, will Jerry have more money in his account than
Amber?
OA. 80> 30 + 6m
OB. 30+6m> 80 + 6m
OC. 6+30m> 80
OD. 30+ 6m> 80

Answers

I’d say 6 plus 30 mg 80

What does perserverance mean to you? What's a goal of yours that you'll fight to achieve?

Answers

Answer:

Doing something despite difficulty or delay in achieving success.

Step-by-step explanation:

Answer:

continued effort to do or achieve something despite difficulties, failure, or opposition

Step-by-step explanation:

Steve is painting the ceiling of a room. the ceiling is in the shape of a rectangle. he has enough paint to cover 198 square feet. the length of the ceiling is 13 feet longer than its width. what are the dimensions of the ceiling? need help asap

Answers

Answer:

Width = 9ft.

Length=22ft.

Step-by-step explanation:

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