Question

Which of the following values is a zero of the expression x²+9x²-x-105

Answer 1

x=7

x=5

x=−3

Explanation:

0-(x^3-9*x^2-x+105)=0

Step by step solution :

STEP

1

:

Equation at the end of step 1

0 - ((((x3) - 32x2) - x) + 105) = 0

STEP

2

:

Checking for a perfect cube

2.1 -x3+9x2+x-105 is not a perfect cube

Trying to factor by pulling out :

2.2 Factoring: -x3+9x2+x-105

Thoughtfully split the expression at hand into groups, each group having two terms :

Group 1: x-105

Group 2: -x3+9x2

Pull out from each group separately :

Group 1: (x-105) • (1)

Group 2: (x-9) • (-x2)