Question

divide -2x^3+21x^2-20x-12 by (x-3) .. can someone walk me thru this? i need to understand it

Answer 1

Do you know synthetic division?

Answer 2

nope

Answer 3

Unfortunately my draw button doesn't work so let's see if this explains it
ax^3 + bx^2 +cx +d divided by (x-k).

line up the coefficients a b c d. What would you have?

Answer 4

ax^5+cx+d?.. im confused :/

Answer 5

or you meant the nubers?

Answer 6

The coefficients are the numbers before x. So it would look like this

-2 21 -20 -12

Answer 7

Now what is your value for k?

Answer 8

-2x^3 + 21x^2 + 20x + 12... and k = -3

Answer 9

We are only going to work worth the coefficients so on a piece of paper write -2 21 -20 -12. Do you see where I got those numbers?

Answer 10

That should be +20

Answer 11

okay!

Answer 12

Hold on as sec

Answer 13

sure

Answer 14

Ok did you write the numbers down?

Answer 15

Now what value will we use for k. Remember our formula ax^3 + bx^2 +cx +d divided by (x-k). What will be the value for k?

Answer 16

-3