Simplify 4x^2+12x-9+(7x^2-x+3)

$4 x^{2} + 12 x - 9 + (7 x^{2} - x + 3)$

Step 1

Remove parentheses.

$4 x^{2} + 12 x - 9 + 7 x^{2} - x + 3$

Step 2

Add $4 x^{2}$ and $7 x^{2}$ .

$11 x^{2} + 12 x - 9 - x + 3$

Step 3

Subtract $x$ from $12 x$ .

$11 x^{2} + 11 x - 9 + 3$

Step 4

Add $- 9$ and $3$ .

$11 x^{2} + 11 x - 6$