Which of the following represents the simplified form of the expression below? (x3 + 4x2 + 12x − 13) − (-2x3 − x2 + 3x + 1)

3x3 + 5x2 + 9x - 14

Step-by-step explanation:

(x3 + 4x2 + 12x − 13) − (-2x3 − x2 + 3x + 1)

= (x3 + 4x2 + 12x − 13) + (2x3 + x2 - 3x - 1)      distribute the -1

= (x3 + 2x3) + (4x2 + x2) + (12x - 3x) + (-13 - 1)   rearrange the terms

= 3x3 + 5x2 + 9x - 14                                            combine like terms

answer is c

step-by-step explanation:

81/12=324/x

x=48