Question

Solving liner system, substitution method

2x-y=23
x-9=-3

Answer 1

2x - y = 23
x - 9 = -3

x - 9 = -3
+ 9 + 9
x = 6
2(6) - y = 23
12 - y = 23
- 12 - 12
-y = 11
y = -11
(x, y) = (6, -11)

Answer 2

the easiest way to solve that would be elimination method, but if you have to do substitution:
x-9=-3
add 9 to each side to get
x=6
then plug 6 into the other equation for x
2(6)-y=23
and solve for y :)