4) Solve for x using y = x - 4.
x = y + 4
Now plug x in to y = 6x - 10.
y = 6(y + 4) - 10
y = 6y + 24 - 10
y = 6y + 14
-5y = 14
y = -14/5
Plug y back in to x = y + 4.
x = -14/5 + 4
x = 1.2
(6/5, -14/5)
5) Make the expressions equal to each other.
2x + 3 = 3x - 6
9 = x
x = 9