Answer:
Its 6.45
Step-by-step explanation:
we first need to know how much is one pane of glass so i divide
15.05÷ 7 and got $2.15
so each one pane of glass is $2.15
than i multiply 2.15 x 3 and got 6.45
So the cost is 6.45
The answer to your question is arithmetic
The answer is y^-1 :) when you have two exponents over a y in a fraction or divison, you always subtract the top from the bottom. hope this helps!
✡ When subtracting negatives, your going to do the same thing has subtracting without negatives.

- - Hope this helps! - -