Question

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

Answer 1

Answer:

x=7

x=5

x=−3

Step-by-step 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)