Answer:
9x^2-3x+4
Step-by-step explanation:
(3x^2+2x^2-5x+7)+(4x^2+2x-3)
5x^2-5x+7+4x^2+2x-3
5x^2+4x^2-5x+2x+7-3
9x^2-3x+7-3
-3x+3c+5d-d
=0+4d
=4d
