Question

if a+b =5, ab =6 and a>b, find the valur of 4( a^2-b^2) -a^3-b^3

Answer 1

$a = 3 \\ b = 2 \\ 4(3 \times 2 - 2 \times 2) - 3 \times 3 - 2 \times 3 \\ 4(6 - 4) - 9 - 6 \\ 4(2) - 15 \\ 8 - 15 \\ - 7$