Answer:
x = 2, y = -3
Step-by-step explanation:
Substitute x = 20 + 6y into 3x - 3y = 15:
[tex]3 (20+6y) - 3y = 15\\60 + 18y - 3y = 15\\60 + 15y = 15\\15y = -45\\y = -3[/tex]
Substitute this back into the equation x = 20 + 6y
[tex]x = 20 + 6 * (-3)\\x = 20 - 18\\x = 2[/tex]
