Simplify (10x-12-3x^2)-(18-4x^2+9x)

$(10 x - 12 - 3 x^{2}) - (18 - 4 x^{2} + 9 x)$

Step 1

Simplify each term.

Apply the distributive property.

$10 x - 12 - 3 x^{2} - 1 \cdot 18 - (- 4 x^{2}) - (9 x)$

Simplify.

Multiply $- 1$ by $18$ .

$10 x - 12 - 3 x^{2} - 18 - (- 4 x^{2}) - (9 x)$

Multiply $- 4$ by $- 1$ .

$10 x - 12 - 3 x^{2} - 18 + 4 x^{2} - (9 x)$

Multiply $9$ by $- 1$ .

$10 x - 12 - 3 x^{2} - 18 + 4 x^{2} - 9 x$

Step 2

Simplify by adding terms.

Subtract $9 x$ from $10 x$ .

$x - 12 - 3 x^{2} - 18 + 4 x^{2}$

Subtract $18$ from $- 12$ .

$x - 3 x^{2} - 30 + 4 x^{2}$

Add $- 3 x^{2}$ and $4 x^{2}$ .

$x + x^{2} - 30$

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

$x^{2} + x - 30$