Question

if the polynomial x 3 + 2 X + a x + b has factor X + 1 and x minus 1 find the value of a and b
for class 10​

Answer 1

Step-by-step explanation:

if X-1 and x+1 is factor then

x= 1 is solution and x= -1 is also a solution.

so if you put x= -1 and +1 in real equation we will get equation= 0

so put x=

1

:- 1 +2 + a+b = 0 (1.)

and

-1

-1 -2 -a +b =0 (2.)

add (1.) + (2.)

2b = 0 so b= 0

not put b= 0 in (1.)

so a= -3

I am sorry I used a method not applicable in 10th boards maybe.

please use method given in your books

sorry