x^3+2^2-2x=2?

Question

i know that the answers are x= -1 and x=+ or -the square root of 2....i just want to know how to solve it. thanks so much.

haha sorry typo...its x^3+x^2-2x=2

Answer 1

Check and make sure you typed that in right. It doesn't seem right.

Answer 2

hi again, I hope my response isn't late.
Well, you will need to do factors, but like all factors, you need to make one side zero. So, move the two over to the other side and you get:
x^3 + x^2 - 2x - 2 = 0

Factor that and you will have:
(x +1) (x^2 - 2) = 0
--> you can always check to see if your factors are correct by multiplying them back out and if you get the same equation from before you factored, then you've got it right

Now maybe you remember by now that once you get that, it's easy to find x; just make each of those factors equal zero. The reason we can do this is because anything times 0 is 0! So one of those factors, and it could be either or both, is a 0. So...

x + 1 = 0 and x^2 -2 = 0
solve for each and you will find that x is equal to -1 for the first one and x is equal to the square root of 2 for the second one. And the reason it is +/- the square root of 2 is because negative times a negative is a positive, as well as a positive times a positive. Also, note that your original equation had x^3, that's a hint to tell you that x will be equal to three different numbers and that is -1, sq.rt 2 and - sq.rt 2.

I hope that helps. ^_^

Answer 3

x^3-2x+4=2 , x^3-2x=2-4 , x^3-2x=2 , then in left side take the x comon facture & do it facturization of 2 squares. it will be x ( x - square root of 2)(x + square root of 2) the answer will be x + 1=0 & x - square root of 2=o or x + square root of 2=0,so it will be x=-1 or x=+ or - square root of 2

Answer 4

Get the X to the right side and get the 2 to the left side.

Answer 5

x^3 + 4 - 2x = 2

x^3 - 2x = -2

x(x^2 - 2) = -2

x(x-sqroot2)(x+sqroot2) = -2

at least here u can see why the answer of x = +/- sq root 2...however, i don't remember how to prove it can also be -1. good luck!

Answer 6

i have the same problem in my pre algebra class. i know what the answer is, but i can't show my work