What is the question ? I don’t get it???
I’d say that the repair costs 75$/hour which then leaves the tax to be 0.09
Wolfram alpha is your best friend in these kind of situations.
I'm also not so great at math but I used KhanAcademy and EDX quite a bit when i was stumped
The sum of 5+2 or 2+5 is 7. It's the same because it doesn't matter if the equation is flipped around in addition.