Question

Y = 10 when x = - 4 , find y when x = 12

Answer 1

y = -30

Explanation:

Set the ratio:
`(x_1)/(y_1) = (x_2)/(y_2)`

Let:

`(x_1 , y_1) = (-4 , 10)\\(x_2 , y_2) = (12 , y)\\`

Plug in the corresponding terms to the corresponding variables:

`(-4)/(10) = (12)/(y)`

First, cross multiply.

`(-4 * y) = (10 * 12)\\-4y = 10 * 12\\-4y = 120`

Next, isolate the variable, y. Divide -4 from both sides of the equation:

`(-4y)/(-4) = (120)/(-4)\\y = (120)/(-4)\\y = -30`

-30 is your answer for y.