What is the sum of the x-values that satisfy the equation 5=x3−2x2−8xx+2?
5 = ( x3 - 2x2 - 8x ) / ( x + 2 ) Note that x can't equal -2.
5(x + 2) = x3 - 2x2 - 8x
5x + 10 = x3 - 2x2 - 8x
0 = x3 - 2x2 - 13x - 10
0 = (x + 2)(x + 1)(x - 5)
Answers: x = -1 x = 5
+980 
