Answer
$2x^{2}+11x$
Work Step by Step
$(5x+8)-(-2x^{2}-6x+8)$
First, let's remove the grouping symbols. To remove the second parentheses, we need to change the sign of every term inside it:
$(5x+8)-(-2x^{2}-6x+8)=5x+8+2x^{2}+6x-8=...$
Simplify by combining like terms:
$...=2x^{2}+(5+6)x+(8-8)=2x^{2}+11x$
