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3 years ago

Which expression represents the calculation "subtract 30 from 40, then multiply by 4

Mathematics

1 answer:

Rzqust [24]3 years ago

3 0

4( 40 - 30)

subtract 30 from 40 is expressed as 40 - 30

then multiply by 4 is expressed as 4 × (40 - 30) or 4(40 - 30) = 40

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The ratio of the number of apples to the number of pears in a basket was 3:5. After 7more apples were added to the basket and 9

atroni [7]

Answer:

Apples = 24

Pears = 40

Step-by-step explanation:

Let u be the unit of fruit in the basket,

number of apples: $3u +7$

number of pears: $5u -9$

now to find u, we equate the two equations.

$3u+7=5u-9$

Now simplify.

$5u-3u=7+9$

$2u=16$

$u=8$

Now we can find the original number of apples and pears by substituting u.

so original number of apples = $3u = 3(8) = 24$

and original number of pears = $5u = 5(8) = 40$

5 0

4 years ago

The braking distance, in feet of a car a Travling at v miles per hour is given.

irakobra [83]

The braking distance is the distance the car travels before coming to a stop after the brakes are applied

a. The braking distances are as follows;

The braking distance at 25 mph, is approximately 63.7 ft.

The braking distance at 55 mph, is approximately 298.35 ft.

The braking distance at 85 mph, is approximately 708.92 ft.

b. If the car takes 450 feet to brake, it was traveling with a speed of 98.211 ft./s

Reason:

The given function for the braking distance is D = 2.6 + v²/22

a. The braking distance if the car is going 25 mph is therefore;

25 mph = 36.66339 ft./s

$D = 2.6 + \dfrac{36.66339^2}{22} = 63.7 \ ft.$

At 25 mph, the braking distance is approximately 63.7 ft.

At 55 mph, the braking distance is given as follows;

55 mph = 80.65945 ft.s

$D = 2.6 + \dfrac{80.65945^2}{22} \approx 298.35 \ ft.$

At 55 mph, the braking distance is approximately 298.35 ft.

At 85 mph, the braking distance is given as follows;

85 mph = 124.6555 ft.s

$D = 2.6 + \dfrac{124.6555^2}{22} \approx 708.92 \ ft.$

At 85 mph, the braking distance is approximately 708.92 ft.

b. The speed of the car when the braking distance is 450 feet is given as follows;

$450 = 2.6 + \dfrac{v^2}{22}$

v² = (450 - 2.6) × 22 = 9842.8

v = √(9842.2) ≈ 98.211 ft./s

The car was moving at v ≈ 98.211 ft./s

Learn more here:

brainly.com/question/18591940

8 0

2 years ago

Solve the following systems by substitution

Paladinen [302]

Answer:

The answer to your question is below

Step-by-step explanation:

Question 1

x = 5 Equation l

2x + y = 10 Equation ll

- Substitute Equation l in equation ll

2(5) + y = 10

y = 10 - 10

y = 0

- Solution (5, 0)

Question 2

x + 16y = 20 Equation l

x = 4y Equation ll

Substitute equation ll in equation l

4y + 16y = 20

20y = 20

y = 20/20

y = 1

-Find x

x = 4(1)

x = 4

-Solution

(4, 1)

Question 3

2x + 8y = 20 Equation l

x = 2 Equation ll

-Substitute equation ll in equation l

2(2) + 8y = 20

4 + 8y = 20

8y = 20 - 4

8y = 16

y = 16/8

y = 2

- Solution

(2, 2)

8 0

4 years ago

Solve for the unknown. Rewrite each phrase as a multiplication sentence. Circle the scaling factor and put a box around the numb

skad [1K]

I hope this helps, i got it from a cheat sheet online

6 0

3 years ago

Tyler ate x fruit snacks, Han ate 3/4 less than that. Write an equation to represent the relationship between the number Tyler a

Citrus2011 [14]

Answer:

0.75x = y

1/4 = y

4 0

3 years ago