In order to add 1/x + 1/y, they need to have the same denominator.
To do this, we can multiply both sides by the variable the denominator is missing, which keeps the expression true and allows it to be solved.
Multiply 1/x by y.
y/xy + 1/y
Multiply 1/y by x.
y/xy + x/xy
x + y/xy
The simplified form of the given expression is (x + y)/xy