Question

The expression
@ganeshie8

Answer 1

\[ax^3-8x^2+bx+6\]is divisible by\[x^2-2x-3\]

Answer 2

Find the values of a and b.

Answer 3

Hint :
factor \(x^2-2x-3\)

Answer 4

\[(x-1)^2\]

Answer 5

doesn't look right, try again

Answer 6

okay.

Answer 7

oh ya... xD

Answer 8

(X-3)(X+1)

Answer 9

That means the given polynomial is divisible by both the factors `x-3` and `x+1`

Answer 10

Remember the factor/remainder theorem ?

Answer 11

It looks something like this :


If `x-k` is a factor of `f(x)`,
then `f(k) = 0`

Answer 12

haven't learn yet.
But i know how to use the long division method

Answer 13

Since `x-3` and `x+1` are the factors of given polynomial,
if you plug x = 3 or x = -1 into the given polynomial, you should get 0.

Answer 14

\(ax^3-8x^2+bx+6\)

Answer 15

plug in x = 3 and set it equal to 0

plug in x = -1 and set it equal to 0

Answer 16

ookay,let me try.

Answer 17

9a-b=22
-a-b=2

Answer 18

is it correct?

Answer 19

I'm getting first equation as

9a + b = 22

Answer 20

second equation looks good

Answer 21

sorry,it ws typo error.

Answer 22

Ohk good :)
two equations and two unknowns, you can solve them

Answer 23

i got a=3 and b=-5

Answer 24

Thank you! @ganeshie8 ^_^