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

Still Need Help?

Join the QuestionCove community and study together with friends!

Sign Up

OpenStudy (anonymous):

I'm working on this.

OpenStudy (anonymous):

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

myininaya (myininaya):

i got a different a

myininaya (myininaya):

let me check what i did

OpenStudy (anonymous):

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

Still Need Help?

Join the QuestionCove community and study together with friends!

Sign Up

myininaya (myininaya):

a=-23/3 ?

myininaya (myininaya):

oops i made a mistake too lol

OpenStudy (anonymous):

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

myininaya (myininaya):

yes a=-6 is right! :)

myininaya (myininaya):

Still Need Help?

Join the QuestionCove community and study together with friends!

Sign Up

myininaya (myininaya):

it doesn't matter what b is

myininaya (myininaya):

b can be any real number

OpenStudy (anonymous):

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

myininaya (myininaya):

yep you can do it that way too

OpenStudy (anonymous):

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

Still Need Help?

Join the QuestionCove community and study together with friends!