Question

If y varies directly with x and y=88 when x=44, find x when y=4.

Answer 1

x=2

Explanation:

Simple ratio:

44/88=x/4

Simplify:

1/2=x/4

Cross multiply:

4=2x

x=2

Answer 2

x = 2

Explanation:

If y varies directly with x then:

`\boxed{y \propto x \implies y=kx}`

where k is the constant of variation.

Given y = 88 when x = 44:

`\implies 88=44k`

Solve for k by dividing both sides by 44:

`\implies (88)/(44)=(44k)/(44)`

`\implies 2=k`

`\implies k=2`

Therefore, the equation is:

`\boxed{y=2x}`

To find the value of x when y = 4, substitute y = 4 into the equation and solve for x:

`\implies 4=2x`

`\implies (4)/(2)=(2x)/(2)`

`\implies 2=x`

Therefore, the value of x when y = 4 is x = 2.