# How do you simplify 18x^2+4-[6(x^2-2)+5]?

Apr 19, 2018

18x^2 + 4 - [6(x^2-2)+5]=color(blue)(12x^2+11

#### Explanation:

Simplify:

$18 {x}^{2} + 4 - \left[6 \left({x}^{2} - 2\right) + 5\right]$

Expand $6 \left({x}^{2} - 2\right)$ to $6 {x}^{2} - 12$.

$18 {x}^{2} + 4 - \left[6 {x}^{2} - 12 + 5\right]$

Simplify $- 12 + 5$ to $- 7$.

$18 {x}^{2} + 4 - \left[6 {x}^{2} - 7\right]$

Simplify $- \left[6 {x}^{2} - 7\right]$ to $- 6 {x}^{2} + 7$.

$18 {x}^{2} + 4 - 6 {x}^{2} + 7$

Collect like terms.

$\left(18 {x}^{2} - 6 {x}^{2}\right) + \left(4 + 7\right)$

Combine like terms.

$12 {x}^{2} + 11$

Apr 19, 2018

Expand the bracket, and collect the like terms.

#### Explanation:

Expand the bracket, you would get:

18${x}^{2}$+4-(6${x}^{2}$-12+5)
18${x}^{2}$+4-6${x}^{2}$+12-5

Collect the like terms:

2${x}^{2}$+11

And it is the final answer!
Hope it helps!