Question

(a+b-2)[a^2+b^2+4(a+b)+4]

Answer 1

$(a + b - 2)(a {}^{2} + b {}^{2} + 4(a + b) + 4)$
$(a + b - 2)(a {}^{2} + b {}^{2} + 4(a + b) + 4) \\ = (a+b - 2)(a {}^{2} + b {}^{2} + 4a + 4b + 4) \\ = a( a {}^{2} + b {}^{2} + 4a + 4b + 4) + b(a {}^{2} + b {}^{2} + 4a + 4b + 4) - 2(a {}^{2} + b {}^{2} + 4a + 4b + 4) \\ = a {}^{3 } + ab {}^{2} + 4a {}^{2} + 4ab + 4a + a {}^{2} b + b {}^{3} + 4ab + 4b {}^{2} + 4b - 2a {}^{2} - 2b {}^{2} - 8a - 8b - 8$