# Homework Help: Rearranging an Equation

1. Dec 14, 2004

### Jeebuz

Hopefully this can be done. It should be relatively simple, I'm just awful at rearranging equations.

I have: x = 90 - sqrt(100+x^2) - sqrt(100+x)

I want to find the value of x.

If someone could guide me through the process I would be eternally grateful. I know there's something about reversing operations, but I get lost in the details. ;)

Last edited: Dec 14, 2004
2. Dec 14, 2004

### cyby

I'm sorry, but I don't see any "b" in the equation.

3. Dec 14, 2004

### Jeebuz

Oops... so sorry. I meant x. I changed it at the last minute. :hangs head in shame:

4. Dec 14, 2004

### cyby

Have you considered squaring the equation and then using the quadratic formula?

5. Dec 14, 2004

### dextercioby

Yeah,a geberal advice...But first,he mustput one (either one) of his square roots in the other side of the equation (left,if i'm not mistaking) and then square.He has to square 2 times in all,of course.Let's hope that by squaring twice he won't be gettin'a nasty 4-th order algebraic equation...