I know it's kind of stupid to ask this question. But I have problems to solve this simple problems. Can someone point me to the right direction? Did I do something wrong in the process or it's a stupid mistake.... :-(
Here's the problem:
$ \frac{5 + 8x}{3 + 2x} = \frac{45 - 8x}{13 - 2x} $
I know that I have to cross multiply
$ \frac{(5 + 8x) \cdot (13 - 2x)}{(3 + 2x) \cdot (45 - 8x)} $
$ \frac{65 + 114x - 16x^2}{135 + 66x - 16x^2} $
Now I do not know how to solve it...
Thank you in advance.