Question

factorise 2a^3 + 16b^3 - 3a - 6b

Answer 1

Answer:

2a^3+16b^3-3a-6b

=2(a^3+8b^3)-3(a+2b)

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

=2(a+2b)(a^2-2ab+4b^2)-3(a+2b)

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

=(a+2b)(2a^2-4ab+8b^2-3)