Question

Subtract (12x+9) from the sum of (5x^2+8x+6) and (8x^2+6x-6)

Answer 1

(5x^2+8x+6) + (8x^2+6x-6) - (12x+9)
= 5x^2 + 8x+  6 +  8x^2 + 6x - 6 - 12x - 9
= 13x^2 + 2x - 9

answer
13x^2 + 2x - 9