Simplify -2x^2+8x-9+4x+7x^2+2

$- 2 x^{2} + 8 x - 9 + 4 x + 7 x^{2} + 2$

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

$5 x^{2} + 8 x - 9 + 4 x + 2$

Add $8 x$ and $4 x$ .

$5 x^{2} + 12 x - 9 + 2$

Add $- 9$ and $2$ .

$5 x^{2} + 12 x - 7$