As we already have the value of y,we can put it into another equation.
Here's how we can solve the equation:
y = 2x+48...(1)
y = 8x...(2)
Put (2) into (1)
(8x) = 2x+48
8x-2x = 48
6x = 48
x = 8...(3)
Put (3) into (1)
y = 8(8)
y = 64
Thus, x=8, y+64
Hope it helps!