# Thread: x^2y^2= 1600, find xy.

1. ## x^2y^2= 1600, find xy.

Can somebody help me with this?
x^2y^2= 1600
Find : xy=??

Also please show solution??

I tried substition but the variables disappear leaving only a number...

2. Just take the square root of both sides. It's a one-step problem. Don't forget that you could have a positive or negative answer.