Question

show that X + 5 is a factor of the polynomial f x = x cube + x square + 3x + 115

Answer 1

If x+5 is a factor of the polynomial, then
f(-5)= 0
F(-5)= (-5)cubed +(-5)squared + 3(-5) + 115
        = -125 + 25 - 15 + 115
        = -100 -15 +115
        = -100 + 100 
        =  0 
Therefore x+5 is a factor of the given polynomial.

Answer 2

Answer:

If x+5 is a factor of the polynomial, then

f(-5)= 0

F(-5)= (-5)cubed +(-5)squared + 3(-5) + 115

        = -125 + 25 - 15 + 115

        = -100 -15 +115

        = -100 + 100 

        =  0 

Therefore x+5 is a factor of the given polynomial.