Question

3x - y = 7

6x - y = 10
When solving this system of equations by elimination, which could be the resulting equation when a variable has been eliminated?
A) 9x - 2y = 17
B) -3y = 24
C) -3x = -3
D) 9x = 17

Answer 1

3x - y = 7
6x - y = 10

if you subtract the second equation from the first to eliminate y you get:
3x-y-(6x-y)=7-10
3x-y-6x+y=-3
-3x=-3

so option C) -3x=-3 is the solution