Solve by Substitution

Answer:
[tex]-9x-10y=12 \ -----(1)\\\\-3x+3=y \ ------(2)\\\\substitute \ y \ in \ (1)\\\\-9x -10(-3x+3) =12\\\\-9x+30x-30=12\\\\21x= 12+30\\21x=42\\x=2\\\\\\substitute \ x \ in \ (2)\\-3\cdot 2+3=y\\-6+3=y\\y=-3[/tex]
x= 2, y = -3