Voltage subtractor with two AC sources?
With a single supply you will need an offset DC voltage on the \$+V_2\$ input to prevent \$V_{out} &lt; 0~V\$.

You can do this by adding a \$2.5~V\$ voltage divider to the \$+\$ input.  You can replace the single resistor to ground with two resistors, of two times the value, one to \$+5~V\$ and one to ground.