Question

Is (3, 6) a solution to this system of equations? 2x + 2y = 18 4x + y = 18

Answer 1

Yes (3,6) is a solution to that because when you plug in the variables you will get 18 as the answer.
2(3)+2(6)=18
6+12=18 ✅
4(3)+6=18
12+6=18 ✅
They are both true

Answer 2

Yes, because the lives intersect at (3,6).

2x+2y = 18
y = -x+9

4x+y = 18
y = -4x+18

-x+9 = -4x+18
3x = 9
x = 3
y = -4x+18 = 6