# How do you combine like terms for 3x^2 + 21x + 5x + 10x^2?

May 15, 2018

See a solution process below:

#### Explanation:

First, group like terms;

$3 \textcolor{red}{{x}^{2}} + 10 \textcolor{red}{{x}^{2}} + 21 \textcolor{b l u e}{x} + 5 \textcolor{b l u e}{x}$

Now, combine the coefficients of the like terms:

$\left(3 + 10\right) \textcolor{red}{{x}^{2}} + \left(21 + 5\right) \textcolor{b l u e}{x}$

$13 \textcolor{red}{{x}^{2}} + 26 \textcolor{b l u e}{x}$

May 15, 2018

Looks like you've already splitted the middle term

#### Explanation:

But splitting isn't what we need here.... add them up
$13 {x}^{2} + 26 x$
Notice that both have $13 x$ as common...
Factorize
$13 x \left(x + 2\right)$