Question

Find the square of $(2a+b)$.

Answer 1

Find the square using an identity.

On applying the identity ${(a+b)}^2=a^2+2ab+b^2$ to find the square of $(2a+b)$ , we get,

$$\begin{gathered} ={(2a+b)}^2 \\ ={\left(2a\right)}^2+2\left(2a\right)\left(b\right)+{\left(b\right)}^2 \\ =4a^2+4ab+b^2 \end{gathered}$$
Hence, using an identity, the square of $(2a+b)$ is $4a^2+4ab+b^2$.