Simplify 12x-(8-9x+3x^2)+6x^2

$12 x - (8 - 9 x + 3 x^{2}) + 6 x^{2}$

Step 1

Simplify each term.

Apply the distributive property.

$12 x - 1 \cdot 8 - (- 9 x) - (3 x^{2}) + 6 x^{2}$

Simplify.

Multiply $- 1$ by $8$ .

$12 x - 8 - (- 9 x) - (3 x^{2}) + 6 x^{2}$

Multiply $- 9$ by $- 1$ .

$12 x - 8 + 9 x - (3 x^{2}) + 6 x^{2}$

Multiply $3$ by $- 1$ .

$12 x - 8 + 9 x - 3 x^{2} + 6 x^{2}$

Step 2

Simplify by adding terms.

Add $12 x$ and $9 x$ .

$21 x - 8 - 3 x^{2} + 6 x^{2}$

Add $- 3 x^{2}$ and $6 x^{2}$ .

$21 x - 8 + 3 x^{2}$

Simplify the expression.

Move $- 8$ .

$21 x + 3 x^{2} - 8$

Reorder $21 x$ and $3 x^{2}$ .

$3 x^{2} + 21 x - 8$