Question

If x-2y=10 and y is three times the value of x, What is the value of x-y? a) -8 b) -4 c) 0 d) 2 e)4

Answer 1

3x = y

x - 2(3x) = 10
x- 6x = 10
-5x = 10
x = -2

3x = y
3(-2) = y
y = -6

Therefore x is -2 and y is -6.

Answer 2

a) 4

Explanation:

y = 3x

Plug it in: x - 2 (3x) = 10 --> x - 6x = 10 --> -5x = 10 --> x = -2

Therefore: y = 3(-2) --> y = -6

x - y = -2 - (-6) = 4