what is the answer to (x^2 + 6x +5) + (4x^3 + 9x^2 - 12)? This expression needs to be simplifyed. The is a 8th grade level question which is Pre-Algebra. There are also muilt-choise answers in this problem.
A. 4x^3 + 10x^2 - 6x - 17
B. 5x^3 + 15x - 7
C. 4x^3 + 10X2 + 6x - 7
D. 4^3 -15x + 7