Question

Answer 1

a) \(5a\left(3a^2-5a+1\right)=15a^3-25a^2+5a\)

b) \(\left(x+2y\right)^2-\left(x-4y\right)\left(x-y\right)=x^2+4xy+4y^2-x^2+xy+4xy-4y^2=9xy\)

Answer 2

a: \(5a\left(3a^2-5a+1\right)=15a^3-25a^2+5a\)

b: \(\left(x+2y\right)^2-\left(x-4y\right)\left(x-y\right)\)

\(=x^2+4xy+4y^2-x^2+xy+4xy-4y^2\)

\(=9xy\)