This is because you're looking for the time (in years) at which your profit is equal to 540. You know what your profit is going to be you just don't know at which year(s)...
Hi, is this a fraction and are you asking for it to be simplified?
If so 8/180 simplifies to 2/45. If you're asking for 8 divided by 180, the answer is 0.04444444 or simply 0.0444... and rounded to the 100th place is 0.04