(a-3b)^5 expand the binomial please
Expand the binomial:( a - 3 b ) ^5 == a^5 - 5 a^4 ( 3 b ) + 10 a^3 ( 3 b ) ^2 - 10 a^2 ( 3 b)^3 + 5 a( 3 b ) ^4 -- ( 3 b )^5 == a^5 - 15 a^4 b + 90 a^3 b^2 - 270 a^2 b^3 + 405 a b^4 - 243 b^5
