Solve the system using substitution.
x + y = 8
y = 3x
A(4, 12)
B(2, 6)
C(1/2, 3/2)
D(-4, -12)
x + y = 8
y = 3x
A(4, 12)
B(2, 6)
C(1/2, 3/2)
D(-4, -12)