#### Answer

An addition of like terms by the help of distributive property.

#### Work Step by Step

By the help of distributive property like terms can add.
Example:
Let’s consider some terms\[3x, 9x\].
Suppose the addition of like terms is A.
Therefore,
\[\begin{align}
& A=3x+9x \\
& =\left( 3+9 \right)x \\
& =12x
\end{align}\]