How do you solve simultaneous equation where one of them involves powers?

Example: y - 3x = 2 , x² + y² = 4 y= 3x + 2 x² + (3x+2)² = 4 10x²+ 12x + 4 = 4 10x²+12x=0 x(10x+12)=0 x=0 or x=-1.2 y=30 + 2 = 2 (0,2) is a solution y = 3-1.2 + 2=-1.6 (-1.2,-1.6) is a solution