Question

if (x+1)and (x-2) are factors of x^3 +ax^2- bx-6 find the value of a and b​

Answer 1

ANSWER:

We the value x+1=0

x=-1

and x-2=0

x=2

in the equation

X3+ax2-bx-6

first we put x=-1

-1+a+b-6=0

a+b=7

EQ.1

and put x=2

8+4a-2b-6=0

2a-b=-1

EQ.2

from eq.1 and eq.2

we get a=2

b=5