Answer: Answer below.
Step-by-step explanation: If x is pi, and y is 1/pi, then multiplying x by y is 1; yes. So, for y, 1 is being divided by pi. The opposite of division is multiplication. If you multiply 1/pi by pi, the pi in the denominator cancels. Just how if it is 5x = 10, dividing by 5 cancels it on the left side, and gets you x = 2.
This is general for everything. If you multiply 2 by 1/2, you get 1. This is because dividing is also like multiplying by its reciprocal. 1/2's reciprocal is 2/1, and multiplying leaves you with 1. Go and use a calculator, it's correct. Actually, any problem a/b × b/a = 1.