Question

(a-2b)^5 expand the following using binomial theorem

Answer 1

=5C0 a^5 + 5C1 a^4(-2b) +5C2a^3(-2b)^2 + 5C3a^2(-2b)^3 +5C4a^1(-2b)^4 +5C5(-2b)^5

= a^5 - 40(a^4)b + 40(a^3)(b^2) - 80(a^2)(b^3)
+ 80a(b^4) -32b^5


i hope this helps :)