This question, because it is worded strangely, is asking for her salary before taxes. We can figure this out because we are given an expression, "(9/10)s", which represents what we want to find.
The equation would be either:
(9/10)s = 486
or
0.9s = 486
To solve, you would divide 486 by 0.9, which gives you $540.
I hope this helps!
