Question

What is the value of x in the equation 1/5 x-2/3y = 30, when y = 15?

Answer 1

The value of x is 200 in the equation 1/5x - 2/3y = 30, when y = 15

Explanation:

Given

equation: x - 2/3y = 30

when y = 15

Plug in y:

1/5x - 2/3(15) = 30

1/5x - 10 = 30

add 10 to both sides,

1/5x - 10 + 10 = 30 + 10

1/5x = 40

multiply both sides by 5

1/5x * 5= 40 * 5

x = 200

Answer 2

x = 200

Explanation:

`(1x)/(5) -(2y)/(3) =30`

Given that, y = 15.

So, to find the value of x you have to replace y with 15 and make the x the subject.

Let us do that now.

`(1x)/(5) -(2*15)/(3) =30\\`

`(1x)/(5) -(30)/(3) =30\\`

`(1x)/(5) =30+ (30)/(3)\\`

`(1x)/(5) =(30)/(1) + (30)/(3)\\`

`(1x)/(5) =(30*3)/(1*3) + (30)/(3)\\`

`(1x)/(5) =(90)/(3) + (30)/(3)\\`

`(1x)/(5) =(120)/(3)`

Use cross multiplication.

`1x*3=120*5\\3x=600`

Divide both sides by 3.

x = 200