Find the value of each variable

Find the solution of system of equation y= x-4 y=4x+2

Prism m and pyramid n have the same base area and the same height. cylinder p and prism q have the same height and the same base perimeter. cone z has the same base area as cylinder y, but its height is three times the height of cylinder y. the figures and have the same volume.

Need solving this 2nd limit problem.