Question

(x +2) is a factor of x ^3 -4x^2- 2x +20. say true or false​

Answer 1

Answer: FALSE

Step-by-step explanation:

Factoring  x2+12x+20 

The first term is,  x2  its coefficient is  1 .

The middle term is,  +12x  its coefficient is  12 .

The last term, "the constant", is  +20 

Step-1 : Multiply the coefficient of the first term by the constant   1 • 20 = 20 

Step-2 : Find two factors of  20  whose sum equals the coefficient of the middle term, which is   12.

2   +   10   =   12   That's it

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  2  and  10 

                     x2 + 2x + 10x + 20

Step-4 : Add up the first 2 terms, pulling out like factors :

                    x • (x+2)

              Add up the last 2 terms, pulling out common factors :

                    10 • (x+2)

Step-5 : Add up the four terms of step 4 :

                    (x+10)  •  (x+2)

             Which is the desired factorization

x= -10 or -2