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

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Answer 1 · 2017-12-03T02:03:42

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

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 $3$ $3$ to $(x^{2} - 1)$ $(x^2-1)$ :

$\Rightarrow 3 x^{2} - 3 - (x^{2} - 7 x + 10)$ $\implies 3x^2-3-(x^2-7x+10)$

Distribute the negative sign and drop the parentheses:

$\Rightarrow 3 x^{2} - 3 - x^{2} + 7 x - 10$ $\implies color(blue)(3x^2)-color(red)(3)-color(blue)(x^2)+7x-color(red)(10)$

Combine like terms:

$\Rightarrow 2 x^{2} + 7 x - 13$ $\implies color(blue)(2x^2)+7x-color(red)(13)$

How do you evaluate 3(x ^ { 2} - 1) - ( x ^ { 2} - 7x + 10)3(x2−1)−(x2−7x+10)3(x ^ { 2} - 1) - ( x ^ { 2} - 7x + 10)?