Question

if p=4-q, prove that p3+q3+12pq=64

Answer 1

Let P = x and Q= y for typing convenience!!
$x = 4 - y \\ x + y = 4 \\ {(x + y)}^{3} = {4}^{3} \\ {x}^{3} + {y}^{3} + 3xy(x + y) = 64 \\ {x}^{3} + {y}^{3} + 3xy(4) = 64 \\ {x}^{3} + {y}^{3} + 12xy = 64$
^_^