Question

Find the value of a and b so that the polynomial x³ - 4x² +ax+b is exactly divisible by x–2 aswell as x + 1.

Answer 1

Step-by-step explanation:

I am also from 9 class

FOLLOW ME

Answer 2

Given

• A polynomial x²-4x²+ax+b
• and have factor x-2 and X+1

To find

• Value of a and b

Solution

• From the remainder Therom

let g(X) = x-2 and x-1

g(X)=0

=>X=2

p(X) =x²-4x²+ax+b

=>p(2) = 4-16+2a+b

=>0=2a+b-12

=>2a+b = 12. ---------> (1)

Let g(X) =1

p(1) = 1-4+a+b

=>0=a+b-3

=>a+b=3 -------> (2)

Now From Equation (1) and (2)

a+b = 3

2a+b =12

_______

a=9

Now putting the value of a in Equation 1

9+b =3

b = -6