Me solve the system of equations using substitution or linear combination (your choice). show all work
3 − 6 = −12
y = 1/2x + 4

Okay so 3x-6(1/2x+4)=-12. 3x-3x-24=-12. x-24=-12.x=-36

OK...I saw the original question with variables.  Using subtraction we get...

y = -1/2x +4    ...  1/2x + y = 4 (add x to both sides so equations are same)
                           3x - 6y = 12

multiply first equation by 6 to be able to subtract  6(1/2x +y = 4)

new equations   3x + 6y = 24
                                3x - 6y = -12   (subtract two equations...

                                 6x = 12   (divide by 6 we get x = 2.

substitute x into original equation to get y...

 y = -1/2x + 4
y = -1/2 (2) + 4
y = -1 + 4
y = 3                 answer (2, 3)