Can someone please explain how to answer this quickly

2x^3y (^ is signaling 3 is an exponent)

Explanation:
The fraction set up is basically subtracting 4x^3y^4 from 2y^3.

Subtract 4 from 2 and you will get 2 which will leave you with 2x^3y^4.

Now subtract the y^4 from y^3. You will end up with y^1 but you write it as y signaling its by itself (or is a 1).

You end up with 2x^3y.

Ibelieve the total for the tip could be $21.90