Question

If x + 2 is a factor of polynomial and a +b = 4, then the values of a and b x2+ax+2b

Answer 1

Answer:  a = 3 and b = 1

According to factor theorem:

x+2

x=-2    

We also know a+b = 4

f(-2) = -2²+-2a+2b = 0    (if it is factor remainder is zero )

4-2a+2b=0

-2a+2b= -4

a-b = -4/-2

a-b = 2

Now add a+b = 4 and a-b = 2

2a = 6

a=3

Therefore substituting it in the equation we get

a+b = 4

3+b = 4

b = 1

So a = 3 and b=1