Question 91970
8x - 4y= 16  ......(1)
y = 2x - 4   ......(2)

substituting the value y in equation (1)

8x - 4*(2x -4) = 16
8x - 8x -16 = 16
0=0

As the equation is true so these equation have infinitely many solutions as they coincide on each other.