Question

Evaluate -3x3 - 4x for x = -1.

Answer 1

put x=1 in the equation you'll have -3(-1)-4(-1)= 7

Answer 2

substitute -1 in place of x:\[-3(-1)^3~-~~4(-1)\]simplify the exponent:\[-3(-1)~-~~4(-1)\]multiply the parenthesis:\[3+4\]add the numbers:\[=7\]