Question

if a-b=4 and ab=2 find a cube-b cube​

Answer 1

a^3 - b^3

= (a-b) (a^2 + b^2 + ab)

= (a-b) (a^2 + b^2 - 2ab + 3ab)

= (a-b) { (a-b)^2 + 3ab}

= 4 (4^2 + 3×2)

= 4 (16 + 6)

= 4×22

= 88