Fractions in Einstein Relativity Theory

[Norway]

Homework Statement

From the formula $$t = \frac{L}{v+c} + \frac{L}{v-c}$$ I've made $$t = \frac{2L}{c}\left(\frac{1}{1 - \frac{v^2}{c^2}}\right)$$. This is the problem:
$$\left(\frac{1}{1 - \frac{v^2}{c^2}}\right) = \left(\frac{1 + \frac{v^2}{c^2}}{1 - \left(\frac{v^2}{c^2}\right)^2}\right)$$
How?

Homework Equations

That's kinda what I'm asking for. :-b

The Attempt at a Solution

I've gotten this far, but no more. I've tried to see how they relate, but I can't figure anything out.

 

[George Jones]

$$\left(\frac{1 + \frac{v^2}{c^2}}{1 - \left(\frac{v^2}{c^2}\right)^2}\right)$$

Factor the difference of squares in the denominator.

 

[xboy]

You remember what $$x^2 - y^2$$ equals to?

 

[Norway]

I get it. Thanks so much! Kinda embarrassing. :-b