Question

The polynomial f(x)=x^3+3x^2+ax+b leaves the same remainder when divided by (x-2) as when divided by (x+1). Find the value of a

Answer 1

I'm working on this.

Answer 2

how? did you take the two remainders adn make them equal

Answer 3

i got a different a

Answer 4

let me check what i did

Answer 5

Yes, you're right myininaya, I made a mistake.

Answer 6

a=-23/3 ?

Answer 7

oops i made a mistake too lol

Answer 8

What I did was set the two equal to 0.
So, x-2=0
and, x+1=0

I got 2 and -1
Then plug them both into the f(x)
8+12+2a+b=-1+3-a+b
Then simplify.
20+2a=2-a
3a=-18
a=-18/3
a=-6

Answer 9

yes a=-6 is right! :)

Answer 10

it doesn't matter what b is

Answer 11

b can be any real number

Answer 12

replace x by 2, replace x by -1, set the results =, solve for a and b right?

Answer 13

yep you can do it that way too

Answer 14

\[-1+3-a+b=8+12+2a+b\]

Answer 15

\[2-a=20+2a\]\[-18=3a\]\[a=-6\]

Answer 16

Thank you both