given f(x)=-3x^2-7x ,find f(7)

Answer:

The change in temperature is -13°F.

Step-by-step explanation:

The change in temperature is,

→ -1 + x = -14

→ x = -14 + 1

→ [ x = -13 ]

Therefore, -13°F is the change.

Answer:

x³ - 4x² + 2x + 4 = 0

Here's how I solved this:

You start off by rewriting the zeros into factors:

1 - √3    →    x = 1 - √3    →    (x - 1 - √3)

  2        →    x = 2           →    (x - 2)

1 + √3   →    x = 1 + √3   →    (x - 1 + √3)

Now you want to multiply the factors together:

     (x - 1 - √3) · (x - 2) · (x - 1 + √3)

- Multiply the first two factors together -

                (x - 1 - √3) · (x - 2)

                              ↓

    (x · x - x · 2 - √3 · x + √3 · 2 - x + 2)

   - Combine like terms and simplify -

    (x · x - x · 2 - √3 · x + √3 · 2 - x + 2)

                              ↓

          (x² - 3x - √3 · x + 2√3 + 2)

      - Now multiply the third factor -

   (x² - 3x - √3 · x + 2√3 + 2)(x - 1 + √3)

                              ↓

(x² · x + x² · √3 - x² - 3x · x - 3x · √3 + 3x - √3 · xx - √3 · x · √3 +√3 · x + 2 · √3 · x + 2 · √3 · √3 - 2 · √3 + 2x + 2 · √3 - 2)

                              ↓

(x³ + x² · √3 - x² - 3x² - 3x · √3 + 3x - √3 + 3x - √3 * x² - x · 3 + √3 · x + 2 · √3 · x + 2 · 3 - 2 × √3 + 2x + 2 √3 - 2)

   - Combine like terms and simplify -

(x³ + x² · √3 - x² - 3x² - 3x · √3 + 3x - √3 + 3x - √3 * x² - x · 3 + √3 · x + 2 · √3 · x + 2 · 3 - 2 × √3 + 2x + 2 √3 - 2)

                              ↓

                 x³ - 4x² + 2x + 4

--------------------------------------------------------------------------------------------------------------

And there we get our solution: x³ - 4x² + 2x + 4  

Answer:200 minutes or 3 hours and 20 minutes

Step-by-step explanation:

multiple 5 and 40 and you’ll get the answer 200

Answer:

200 minutes which is 3 hours and 20 minutes.

Step-by-step explanation:

FIrst you multiply 5 x 40 which equals 200

To find out how many hours there are in 200 minutes, you divide it by 60.

200 divided by 60 = 3.3...

3 hours. The remander is 20 minuites and there you have it.

The cost of each bag of apple is $6.35

If Miguel buys eggs and apples at the store.

• He pays a total of $56.97.

• He pays a total of $6.17 for the eggs.

• He buys 8 bags of apples that each cost the same amount

The correct equation that represents the statement will be given as:

Make x the subject of the formula

8x = 56.97 - 6.17

8x = 50.8

x = 50.8/8

x = 6.35

Hence the cost of each bag of apple is $6.35

Learn more on equations here: https://brainly.com/question/2972832

Answer:

I think it is 249 for the first one and the second one i dont know sorry

Step-by-step explanation:

Answer:

5x+12+x'

_______

2x'-2x-4

'=2

Answer:

$2,139 was the total amount the school raised.

Step-by-step explanation:

35% of 600= 210

210+600 = $810

10% of 810= 81

810-81= $729

6th Graders= $600

7th Graders= $810

8th Graders= $729

Answer:

Right ear     a.d. = auris dextra

Step-by-step explanation:

mathematics may not have been the best place to ask this question.

Answer:

ad meaning right ear so C

Step-by-step explanation:

Answer:

64 tea bags for 9.28

Step-by-step explanation:

Answer:

a=35 b=14 c=5

Step-by-step explanation:

a

180-55-90=35

b

b+6=20

b=14

c

4c-6=14

14+6=20

20/4=5

Answer:

y=

x

​

−2

y=−

x

​

−2, x≥0

​

y=−

x−2, x≥0

​

Step-by-step explanation:

Answers;

Question 1 answer: The first and last option.

Question 1 explanation: 2(4x + 2) is 4x = 12 = 2 = 14 x 2 = 28 and 8x + 4 is 8 x 4 = 32 + 4 = 36 which is 8 more than 28 then, 3x = 9 + 2 + 3 x 2 = 28.

2(4x + 2) = 28 and 8x + 4 equals 36 which is 8 more and they're both equivalent to 2(3x + 2 + x) because 2(3x = 2 = x) equals 28.

Answer:

y-9=2(x-3)

Step-by-step explanation:

y-y1=m(x-x1)

y-9=2(x-3)

Answer:

His son is 3 years old.

Step-by-step explanation:

33 years old ... 3 less than ....  =  36

36/12  =  3

Answer:

(-4,-5)

Step-by-step explanation:

The coordinates of the midpoint for x = sum of x/2=2

The coordinates of the midpoint for y = sum of y/2=-2

firstly to work out x coordinate:

[tex] \frac{x + 8}{2} = 2[/tex]

rearrange to find x which is -4

work out y coordinate:

[tex]\frac{y + 1}{2} = - 2[/tex]

rearrange to find y which is -5

so coordinates are (-4,-5)

Answer:

2 1/2 hours

Step-by-step explanation:

For 1 hour, it would travel 90 miles.

For half of 90 which is 45 it would travel 1/2 hr.

225-180 is 45 miles, which is another half hr.

2 hrs plus 1/2 hr is 2 1/2 hours.

Answer:

  10 ml, 0.1 l, 15 cl, 0.5 l, 1000 ml

Step-by-step explanation:

m is an SI prefix for milli-, meaning 1/1000.

c is an SI prefix for centi-, meaning 1/100.

Expressed in liters, these volumes are ...

  0.10 l

  0.50 l

  1000/1000 l = 1.00 l

  10/1000 l = 0.01 l

  15/100 l = 0.15 l

In order from smallest to largest, they are ...

  0.01 l, 0.10 l, 0.15 l, 0.50 l, 1.00 l

In the original units, the order is ...

  10 ml, 0.1 l, 15 cl, 0.5 l, 1000 ml

Answer:

3 dregreess 5 degrees temperature

You likely mean to write the differential equation,

y'' - 2y' + y = exp(x)

The homogeneous part

y'' - 2y' + y = 0

has characteristic equation

r² - 2r + 1 = (r - 1)² = 0

with a root at r = 1 with multiplicity 2, so the characteristic solution is

y = C₁ exp(x) + C₂ x exp(x)

For the particular solution, we assume an ansatz

y = ax² exp(x)

where a is an unknown constant. Differentiating the ansatz twice:

y' = ax² exp(x) + 2ax exp(x) = (ax² + 2ax) exp(x)

y'' = (ax² + 2ax) exp(x) + (2ax + 2a) exp(x) = (ax² + 4ax + 2a) exp(x)

Substitute y and its derivatives into the DE:

(ax² + 4ax + 2a) exp(x) - 2 (ax² + 2ax) exp(x) + ax² exp(x) = exp(x)

Solve for a :

(ax² + 4ax + 2a) - 2 (ax² + 2ax) + ax² = 1

2a = 1

a = 1/2

Then the particular solution is

y = 1/2 x² exp(x)

The general solution is then

y = C₁ exp(x) + C₂ x exp(x) + 1/2 x² exp(x)

Hey there!

3(4 - 5x) = 3(4x + 3)

3(4) + 3(-5x) = 3(4x) + 3(3)

12 - 15x = 12x + 9

-15x + 12 = 12x + 9

SUBTRACT 12x to BOTH SIDES

-15x + 12 - 12x = 12x + 9 - 12

SIMPLIFY IT!

-27x + 12 = 9

SUBTRACT 12 to BOTH SIDES

-27x + 12 - 12 = 9 - 12

CANCEL out: 12 - 12 because it gives you 0

KEEP: 9 - 12 because it helps solve for the x-value

NEW EQUATION: -27x = 9 - 12

SIMPLIFY IT!

-27x = -3

DIVIDE -27 to BOTH SIDES

-27x/-27 = -3/-27

CANCEL -27/-27 because that gives you 1

KEEP: -3/-27 because it helps solve for the x -value

NEW EQUATION: x = -3/-27

SIMPLIFY IT/REDUCE the FRACTION!

x = 1/9

Therefore, your answer is: x = 1/9

Good luck on your assignment and enjoy your day!

~Amphitrite1040:)

Answer:

8/10

Step-by-step explanation:

id hope your have a great day

Answer:

80%

Step-by-step explanation:

80÷100=.8 which is 80%

27) 115=5(5a-2)

115= 25a-10

125=25a

a=5

28) -72=-x-6(x+5)

-72=-7x-30

-42=-7x

x=6

i did two of them. now i gtg so won't do the rest

Answer:

14.9

Step-by-step explanation:

50-5.03 = 44.97

44.97 ÷ 3 = 14.99

Answer:

Using the number 4 as a place holder I think it would be 20 days before she has both chores on the same day

Answer:

x = 3

Step-by-step explanation:

a triangle has 180 degrees in all

a square for an angle is 90 degrees

we can add them all together and get 180

90 + 45 + 8x + 21 = 180

combine like terms

156 + 8x = 180

subtract 156 to each side

8x = 24

then find x

x = 3

Answer:

x=3

Step-by-step explanation:

So the sum of angles of triangle is always 180 degrees.

We already have 45 and 90 but 8x+21 is unknown.

We can solve this by making an equation which is

45 + 90 + (8x+21) = 180.

If we solve this it will be

8x+21+135=180

8x+156 (-156) =180 (-156)

8x (/8) = 24 (/8)

x=3

You have to add.

Step-by-step explanation:

I'm trash at math.