Question

solve 5x^3-6x^2-4x-8=0

Answer 1

I would factor by grouping... what can you take out of this... what do they have in common?

\[5x ^{3}-6x ^{2}\]

Answer 2

@notsmartatall ?

Answer 3

nun of them are in common

Answer 4

\[x ^{2}(5x-6)\]

Answer 5

Do you understand how I took out 2 x variables?

X^3 + X^2

They both have 2 x variables... so I took 2 out @notsmartatall

Answer 6

ohhh ya that makes sense now

Answer 7

So what about

(-4x-8)

What can you take out of this? What is the highest number that you can divide both of the numbers by?

Answer 8

-4

Answer 9

-4(x+2)

Right... so now we have another part

Answer 10

\[x ^{2}(5x-6)-4(x+2)\]

Answer 11

So you understand I just lined everything up right here @notsmartatall ?

Answer 12

ya ok i get it

Answer 13

\[(x ^{2}-4)(5x-6)(x+2) = 0\]

Answer 14

So here I pulled down what ever was in parenthesis already. Then what was on the outside of the parenthesis I put them together in the first set.

Answer 15

\[x ^{2}-4 = 0 \]

Answer 16

We must solve all of them one by one now... so that one is first. Can you solve for x?

Answer 17

x=2

Answer 18

Yes!

Answer 19

So that is one answer... now we move onto the next..

Answer 20

5x-6 = 0

Solve for x

Answer 21

x+2 = 0

Solve for x

Answer 22

x=6/5

Answer 23

Good!

Answer 24

x=-2

Answer 25

Good!

Answer 26

x = 2, -2, 6/5

Answer 27

So you are very smart!

Answer 28

ahhaha thank you!!