Simplify (11x+2x^2)+(-7x-3x^2+4)

$(11 x + 2 x^{2}) + (- 7 x - 3 x^{2} + 4)$

Remove parentheses.

$11 x + 2 x^{2} - 7 x - 3 x^{2} + 4$

Subtract $7 x$ from $11 x$ .

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

Subtract $3 x^{2}$ from $2 x^{2}$ .

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