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3 years ago

Solve. 4/7 = 21/ x - 3

Mathematics

2 answers:

kicyunya [14]3 years ago

7 0

4/7 = 21/ (x - 3)

multiply by (x-3) on each side

4(x-3)/7 =21

multiply by 7 on each side

4(x-3) = 21*7

distribute

4x-12 = 147

add 12 to each side

4x = 159

divide by 4

x = 159/4

change back to a mixed number

4 goes into 159 39 times with 3 left over

39 3/4

Choice C

PtichkaEL [24]3 years ago

4 0

4/7 = 21/(x-3)

Multiply x-3 on to both sides to get

4(x-3)/ 7 =21

Multiply both sides by 7 to get

4(x-3) = 144

Multiply to get

4x - 12 = 144

Add 12 on both sides to get

4x = 156

Divide both by 4 to get

156/4

Or

39

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Jake and his dad are making flags for a scouting project.They are going to make(6,12,18) flags . Each flag takes (2/3,3/4,5/6) o

evablogger [386]

Answer:

The total yards of cloth needed for the flags = 28

Step-by-step explanation:

Given:

Jake and his dad are making (6,12,18) different types of flags.

Each flag takes $(\frac{2}{3},\frac{3}{4},\frac{5}{6})$ of a yard of cloth.

To find the total yards of cloth needed in all.

Solution:

Flag A :

Each flag requires = $\frac{2}{3}$ of a yard of cloth

Total number of this flag = 6

Total cloth required for this flag = $\frac{2}{3}\times 6 = 4\ yd$

Flag B:

Each flag requires = $\frac{3}{4}$ of a yard of cloth

Total number of this flag = 12

Total cloth required for this flag = $\frac{3}{4}\times 12 = 9\ yd$

Flag C:

Each flag requires = $\frac{5}{6}$ of a yard of cloth

Total number of this flag = 18

Total cloth required for this flag = $\frac{5}{6}\times 18 = 15\ yd$

Thus, total yards of cloth needed for the flags = $4\ yd+9\ yd+15\ yd =28\ yd$

8 0

4 years ago

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vladimir2022 [97]

Answer:

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Step-by-step explanation:

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3 years ago

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4 years ago

The driver of a 810.0 kg car decides to double the speed from 23.6 m/s to 47.2 m/s. What effect would this have on the amount of

Setler [38]

Answer:

KEi = 2.256×10^5 J
KEf = 9.023×10^5 J
4 times as much work

Step-by-step explanation:

The kinetic energy for a given mass and velocity is ...

KE = (1/2)mv^2 . . . . . m is mass

At its initial speed, the kinetic energy of the car is ...

KEi = (1/2)(810 kg)(23.6 m/s)^2 ≈ 2.256×10^5 J . . . . . m is meters

At its final speed, the kinetic energy of the car is ...

KEf = (1/2)(810 kg)(47.2 m/s)^2 ≈ 9.023×10^5 J

The ratio of final to initial kinetic energy is ...

(9.023×10^5)/(2.256×10^5) = 4

4 times as much work must be done to stop the car.

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You know this without computing the kinetic energy. KE is proportional to the square of speed, so when the speed doubles, the KE is multiplied by 2^2 = 4.

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3 years ago

Angle GHI and angle JHI are supplementary. Angle GHI measures (28x + 40)° and angle JHI measures (7x)°. What is the measure of a

muminat

Two angles are supplementary if their sum is 180 degrees.

Here we are given:

Angle GHI measures (28x + 40)° and angle JHI measures (7x)°.

Sum of angle GHI and JHI is 180.

$angle GHI + angle JHI = 180$