x + 8 = y --- (1)
3x = y --- (2)
Notice that both (1) and (2) have y on the right hand side of their equation.
Thus, we can just compare the two equations directly:
x + 8 = 3x
3x - x = 8
2x = 8
x = 8 / 2
x = 4
Substituting x = 4 into (2), we have:
y = 3x
y = 3(4)
y = 12
Hence, x = 4 and y = 12.