Question

Solve: ${\left(a+b\right)}^2-a^2-b^2=$?

Answer 1

Hint- Here, we will be using the formula for ${\left(a+b\right)}^2$.As the problem depends on the algebraic identities.

As we know that ${\left(a+b\right)}^2=a^2+b^2+2ab$
Using the above formula in the given expression which needs to be simplified.
$$\begin{gathered} {\left(a+b\right)}^2-a^2-b^2=a^2+b^2+2ab-a^2-b^2=2ab \\ \therefore {\left(a+b\right)}^2-a^2-b^2=2ab \end{gathered}$$

Note- In these types of problems, the given expression which needs to be simplified is done by using some appropriate formula. In this particular problem, in the given expression ${\left(a+b\right)}^2$ is there so we will simply it by using the formula for ${\left(a+b\right)}^2$.