# How do you evaluate 3(x ^ { 2} - 1) - ( x ^ { 2} - 7x + 10)?

Dec 3, 2017

The simplified expression is $2 {x}^{2} + 7 x - 13$.

#### Explanation:

Since this isn’t an equation, but rather an expression, it can only be simplified, not evaluated.

So let’s simplify it.

First distribute the $3$ to $\left({x}^{2} - 1\right)$:

$\setminus \implies 3 {x}^{2} - 3 - \left({x}^{2} - 7 x + 10\right)$

Distribute the negative sign and drop the parentheses:

$\setminus \implies \textcolor{b l u e}{3 {x}^{2}} - \textcolor{red}{3} - \textcolor{b l u e}{{x}^{2}} + 7 x - \textcolor{red}{10}$

Combine like terms:

$\setminus \implies \textcolor{b l u e}{2 {x}^{2}} + 7 x - \textcolor{red}{13}$