Eliminate redundant parentheses
(5x 2 - 9x +2 ) + ( -3x2 + 2x 4) 
5x 2-9x+2 -3x2+ 2x +4 
Add the numbers
5x2 -9x +2 -3x2 +2x+4 
5x2 -9x +6 -3x2 + 2x 
Combine like terms
5x2 -9x +6 - 3x2 +2x 
2x2 -9x +6 + 2x 
Combine like terms
2x2 -9x +6 +2x 
2x2 -7x +6 
Solution
2x2 - 7x +6