Question

What is the value of x in the equation 1/4 x- 2/3y=30, when y=15

Answer 1

x would be equal to 160.

Explanation:

When y=15,
`(2)/(3)*15=10`.

So, we can rephrase this as
`(1)/(4)x-10=30`.

Because we need the end result to be equal to 30, we need to get
`40-10=30.`

Because we need to make 40 with the fraction
`(1)/(4)`, we can have x be equal to 160, and we would get
`(160)/(4)=40`.

So, we know that x = 160.

Answer 2

x = 40

Explanation:

x -
`(2)/(3)`y = 30 Replace y with 15

x -
`(2)/(3)`(`15) = 30
`(2)/(3)`
`((15)/(1)`) =
`(30)/(10)` = 3

x - 10 = 30 Add 10 to both sides of the equation

x = 40

Check:

x -
`(2)/(3)`y = 30

40 -
`(2)/(3)`(15) =30

40 - 10 = 30