What is 3x-3y equals 12 and 4y-8x equals -16?

Answer 1

This is a simultaneous equation question.

Arrange both equations in line with their letters and numbers and then simplify them:

(3x-3y = 12) divide all terms by 3

(-8x+4y = -16) divide all terms by 4

This will give you:

x - y = 4

-2x+y = -4

Adding both equations together will give you:

-x = 0

So x = 0, substitute this value for x in the original equations to find the value of y:

x = 0 and y = -4

Note that -3*-4 = 12 and that +4*-4 = -16