Question

\(25a^2+4b^2-20ab\)

Answer 1

\(25a^2+4b^2-20ab=\left(5a\right)^2-2.5a.2b+\left(2b\right)^2=\left(5a-2b\right)^2\)

Answer 2

`= (5a)^2 - 2 . 5 . 2 ab + (2b)^2`

`= (5a-2b)^2`