what is the solution to this system of equations?
x-2y=15
2x + 4y=-18
Answer:
x = 3; y = -6
Step-by-step explanation:
x - 2y = 15
2x + 4y = -18
Multiply both sides of the first equation by 2. Write the second equation below it, and add the two equations.
2x - 4y = 30
(+) 2x + 4y = -18
---------------------------
4x = 12
4x/4 = 12/4
x = 3
Now we substitute 3 for x in the first equation and solve for y.
x - 2y = 15
3 - 2y = 15
-2y = 12
y = -6
Answer: x = 3; y = -6
An advocacy group claims that the mean braking distance of a certain type of tire is 75 feet when the car is going 40 miles per hour. In a test of 80 of these tires, the braking distance has a mean of 77 and a standard deviation of 5.9 feet. Find the standardized test statistic and the corresponding p-value.
Answer:
The calculated value t = 3.032 > 1.9904 at 5% level of significance
Step-by-step explanation:
Step(i):-
Given mean of the population 'μ'=75 feet
Given mean of the sample(x⁻) = 77
Given standard deviation of the sample(S) = 5.9
Given sample size 'n' =80
Step(ii):-
Test statistic
[tex]t=\frac{x^{-} -mean}{\frac{S}{\sqrt{n} } }[/tex]
[tex]t=\frac{77-75}{\frac{5.9}{\sqrt{80} } }[/tex]
t = 3.032
Degrees of freedom ν=n-1 = 80-1 =79
tabulated value = 1.9904 at 5% level of significance
The calculated value t = 3.032
Final answer:-
The calculated value t = 3.032 > 1.9904 at 5% level of significance
What is the slope of the line that passes through the points (-6, 8) and (−16,33)? Write your answer in simplest form.
Answer:
[tex]-\frac{5}{2}[/tex]
Step-by-step explanation:
[tex]\frac{change in Y}{change in X}[/tex]
plug in points:
[tex]\frac{8-33}{-6+16}[/tex]
[tex]\frac{-25}{10}[/tex]
Simplify:
[tex]-\frac{5}{2}[/tex]
Please helps What is the base and the exponent of [tex]7^4[/tex]
Answer:
Base: [tex]7[/tex]
Exponent: [tex]4[/tex]
Step-by-step explanation:
What is the base and the exponent of [tex]7^4[/tex]?
If you want to know the base, you will have to look at the whole number. The whole number is 7. So that means the base is 7. The number on top of the whole number(exponent) is gonna be the exponent. The number 4 is on the exponent. So in that case, the number 4 is the exponent. So the base is 7 and the exponent is 4.
Hope this helps!
Answer:
Base(7)
Exponent(4)
Step-by-step explanation:
A base is always the whole number. In this exponent, the whole number you see is 7. So that means 7 is the base number. The exponent is the small number you see on top of the whole number(base). The exponent on top of the whole number is 4. So the base number is 7 and the exponent is 4.
Hope this helped you a lot!
Which of the following is equivalent equation
Answer:
Option 1 F
Step-by-step explanation:
If all the terms in an equation have a common factor, then you can divide all the terms by that common factor and receive the same answer. In this question, all the terms are divisible by 3 (3, 12 and 6 can all divide by 3) so we can divide them all by 3 while keeping the equation equal, which gives us:
3y/3 = 12x/3 -6/3
y = 4x - 2
Hope this helped!
beginning of Tear Assessment Grade 8 Mathematics
37 OT 42
A rectangular prism and its dimensions are shown in the diagram.
6.5 in.
5 in.
7.5 in.
What is the total surface area of this prism in square inches?
Answer: 237.5 square inches
Step-by-step explanation:
Total surface area of rectangular prism = 2 (lw+wh +hl)
, where l= length
w = width
h= height
Given: A rectangular prism and its dimensions are.
6.5 in. ,5 in. ,7.5 in.
Then, the total surface area of this prism = 2 (6.5×5 + 6.5 × 7.5 + 5×7.5)
= 2 (32.5+ 48.75 + 37.5)
= 2 (118.75)
= 237.5
Hence, the total surface area of this prism = 237.5 square inches
Answer:
237.5
Step-by-step explanation:
took a test
The rectangle below has an area of x^2+11x+28x 2 +11x+28x, squared, plus, 11, x, plus, 28 square meters and a length of x+7x+7x, plus, 7 meters. What expression represents the width of the rectangle?
Answer:
[tex]Width = x + 4[/tex]
Step-by-step explanation:
Given
Shape: Rectangle
[tex]Area = x^2 + 11x + 28[/tex]
[tex]Length = x + 7[/tex]
Required
Determine the width
For a rectangle:
[tex]Area = Length * Width[/tex]
Substitute values for Length and Area
[tex]x^2 + 11x + 28 = (x + 7) * Width[/tex]
Factorize the expression on the left hand side
[tex]x^2 + 7x + 4x + 28 = (x + 7) * Width[/tex]
[tex]x(x + 7) + 4(x + 7) = (x + 7) * Width[/tex]
[tex](x + 7)(x + 4) = (x + 7) * Width[/tex]
Divide both sides by x + 7
[tex]Width = x + 4[/tex]
A manufacturer knows that their items have a normally distributed lifespan, with a mean of 8.4 years, and standard deviation of 0.6 years. The 4% of items with the shortest lifespan will last less than how many years?
Answer:
7.35 years
Step-by-step explanation:
Given that :
mean = 8.4
standard deviation = 0.6
From the negative z tables, the corresponding data for 0.04 = -1.75
So, using the z-score formula:
[tex]z = \dfrac{x - \mu}{\sigma}[/tex]
[tex]-1.75 = \dfrac{x - 8.4}{0.6}[/tex]
-1.75 × 0.6 = x - 8.4
- 1.05 = x - 8.4
x = -1.05 + 8.4
x = 7.35 years
the shortest lifespan will last less than 7.35 years
∴ the longest 4% will have lifespans longer than x = 8.4 + 1.75(0.6)
= 9.45 years
can someone pleaseee help me
Answer
13/4
Step-by-step explanation:
In the quadrilateral,all the sides are equal,but diagonals are not equal is called?
Answer:
I think it would be a rhombus.
I will give the brainiest
Tim has 74 socks, all in pairs. He has 1 more pair of white socks than black socks. How many
individual socks of each color does he have?
black socks
white socks
Answers:
36 individual black socks
38 individual white socks
Check: 36+38 = 74 total individual socks
====================================================
Work Shown:
b = number of pairs of black socks
w = number of pairs of white socks
w = b+1 since he has 1 more pair of white socks compared to black socks
2b = number of individual black socks
2w = number of individual white socks
2b+2w = total number of individual socks
2b+2w = 74
2b+2(b+1) = 74 .... plug in w = b+1
2b+2b+2 = 74 ... distribute
4b+2 = 74
4b = 74-2 .... subtracting 2 from both sides
4b = 72
b = 72/4 ... dividing both sides by 4
b = 18 is the number of pairs of black socks he has
2b = 2*18 = 36 is the number of individual black socks he has
w = b+1 = 18+1 = 19 is the number of pairs of white socks he has
2w = 2*19 = 38 is the number of individual white socks he has
2b+2w = 36+38 = 74 individual socks overall
For each of the following quadrilaterals, Write all the properties that must be true. Four Right angles Only One pair of parallel sides Two pairs of parallel sides All sides congurantParallelogramSquareRhombus
Answer:
Step-by-step explanation:
THE PROPERTIES:
A. Four right angles
B. Only 1 pair of parallel sides
C. Two pairs of parallel sides
D. All sides congruent - all sides having the same shape and size
FOR A PARALLELOGRAM,
Property C applies
FOR A SQUARE,
Properties A, C and D apply
FOR A RHOMBUS,
Properties C and D apply
A genetic test is used to determine if people have a predisposition for thrombosis, which is the formation of a blood clot inside a blood vessel that obstructs the flow of blood through the circulatory system. It is believed that 3% of people actually have this predisposition. The genetic test is 98% accurate if a person actually has the predisposition, meaning that the probability of a positive test result when a person actually has the predisposition is 0.98. The test is 97% accurate if a person does not have the predisposition. What is the probability that a randomly selected person who tests positive for the predisposition by the test actually has the predisposition? (Round your answer to four decimal places.)
The perimeter of a certain rectangle is 16 times the width. The length is 12cm more than the width. Find the length of the rectangle. Show work.
Answer:
Step-by-step explanation:
width = w
length = 12 + w
Perimeter of rectangle = 2*length + 2*width since perimeter measures the distance around an object.
The perimeter of a certain rectangle is 16 times the width means 2 * (12 + w) + 2 *w = 16w
24 + 2w + 2w = 16w
24 + 4w = 16w subtract 4w from both sides
24 = 12 w divide both sides by 12
2 = w
width = 2 cm
length = 12 + 2 = 14 cm
I don't get it can u please show me how to do it step by step
Step-by-step explanation:
6.)
|x - 6| = 5
x + 6 = 5
x = 5 - 6
x = - 1
7.)
|3x - 7| = 12
3x + 7 = 12
3x = 12 - 7
3x = 5
x = 5/3
8.)
|2x + 9| - 10 = 5
2x + 9 - 10 = 5
2x - 1 = 5
2x = 1 + 5
2x = 6
x = 6/2
x = 3
42 ÷ [15 − (3 + 5)]
help me on this tricky problem
Answer:
6
Step-by-step explanation:
42 / [15 - (3 + 5)]
42 / [15 - 8]
42 / 7
Answer: 6
7x- 8y = -12
-4x + 2y = 3
Answer:
Step-by-step explanation:
7x - 8y = -12
-16x + 8y = 12
-9x = 0
x = 0
-4(0) + 2y = 3
2y = 3
y = 3/2
(0, 3/2)
Help me please 2(x-4) = 6x - 6
Answer:
-1/2 = x
Step-by-step explanation:
2 (x - 4) = 6x - 6 (distribute)
2x - 8 = 6x - 6 ( subtract 2x from each side)
- 8 = 4x - 6 ( add 6 to both sides)
-2 = 4x ( divide each side by 4)
x = -2/4 which simplifies to -1/2
Answer:
x is -1/2 (negative one half)
Step-by-step explanation:
Apply distributive property on the left in order to get rid of the parenthesis, and then group all terms in x on the right, and all numerical terms on the left. Combine like terms, and finally solve for "x":
2 (x - 4) = 6 x - 6
2 x - 8 = 6 x - 6
6 - 8 = 6 x - 2 x
-2 = 4 x
x = -2/4
x = -1/2
Is sqrt -5 rational, irrational or imaginary?
Answer:
Imaginary
Step-by-step explanation:
[tex] \sqrt{ - 5} \: is \: imaginary[/tex]
Si se reduce en 5 unidades de mil el número 23 657, ¿cuál número se obtiene? a) 23 607 b) 18 657 c) 23 157 d) 23 652
Answer:
a 23 607
Step-by-step explanation:
What is 9+(5x10)+1-(15x2)
Answer:
30
Step-by-step explanation:
=9 + 5 x 10 + 1 + -15 x 2 = ( 5 x 10 ) + ( −15 x 2) + ( 9 +1 ) = 5 x 10 + −15 x 2 + 10
Answer:
30
Step-by-step explanation:
9+(5x10)+1-(15x2)
First, we must evaluate the numbers in the parentheses. (5x10) is 50, and (15x2) is 30. Since we have the answers to that, we can now put the expression as: 9 + (50) + 1 - (30).
9 + (50) = 59
59 + 1 = 60
60 - (30) = 30
Therefore, the answer is 30.
Hope this helped!
Solve for the specified variable.
(c+d)
Solve Q=
for d.
2
Answer:
2Q -c = d
Step-by-step explanation:
Q= ( c+d)/2
Multiply each side by 2
2Q = ( c+d)/2 *2
2Q = ( c+d)
Subtract c from each side
2Q - c = c+d-c
2Q -c = d
Steps to solve:
Q = (c+d)/2
~Simplify
Q = 1/2c + 1/2d
~Subtract 1/2c to both sides
Q - 1/2c = 1/2d
~Divide 1/2 to both sides
d = 2q - c
Best of Luck!
what is an algebraic word phrase for 49 + M
Answer:
slader
Step-by-step explanation:
what is the value of the expression below when y=5? y^2-3y+6
Answer:
y = 5
y^2 - 3y + 6
= 5^2 - 3(5) + 6
= 25 - 15 + 6
= 10 + 6
= 16
How many solutions will there be for a quadratic equation of the form ax2 + bx+c = 0 if the discriminant, b2 - 4ac, is negative?
1.)There will be two complex solutions.
2.)There will be one real solution.
3.)There will be two real solutions.
3.)There will be no solutions.
The battery in camilles old phone can’t last for 4.2 hours .she bought a new phone that’s gas battery that can last 60% longer . How long can the battery on camilles new phone last?
Answer:
6.72 Hours
Step-by-step explanation:
Since the new phone can last 60% Longer than 4.2 hours, we multiply 4.2 by .6 and then add it back to 4.2
4.2 X 60% = 2.52
2.52+4.2=6.72
Therefore, the new phone can last 6.72 hours
A copy machine makes 112 copies in minutes3 and30 seconds. How many copies does it make per minute?
Answer:
32
Step-by-step explanation:
It takes a total of 210 seconds to make 112 copies.
Divide 210 by 60 to get 3.5
(If you divide 210 by 3.5 you get 60 sec.)
Next, divide 112 by 3.5
The copy machine makes 32 copies in one minute.
the sum of three numbers is 116. The first number is 6 more than the third. The second number is 3 times the third. What are the numbers?NEED DONE ASAP
Answer:
107
Step-by-step explanation:
sum means addition so 3 + 6 = 9 116 - 9 = 107 hope it helps <3
Astronauts who traveled to the moon were able to float slightly as they walked along its surface. Why wee the astronauts able to do this?
Answer:
C.
Step-by-step explanation:
the farther you get from Earth, the less the gravitational force i, so if your in space, you will have more weight next to earth than you will next to the moon.
Carissa counts by 5s from 32 to 62. Which number does carissa count?
Answer:
32, 37, 42, 47, 52, 57, 62.
Step-by-step explanation:
It is given that Carissa counts by 5s from 32 to 62.
It means, we have to add 5 in the number to get the next number.
Add 5 in 32.
[tex]32+5=37[/tex]
Now, add 5 in 37.
[tex]37+5=42[/tex]
Similarly, continue the process.
[tex]42+5=47[/tex]
[tex]47+5=52[/tex]
[tex]52+5=57[/tex]
[tex]57+5=62[/tex]
Therefore, the numbers counted by carissa are 32, 37, 42, 47, 52, 57, 62.
Answer:
It is 47
Step-by-step explanation: