Here's my step-by-step explanation:
We're just gonna factor.
If your teacher has spoken of FOIL, then he/she has probably said that it means First Outer Inner Last and that it helps with distributing problems like these.
Right, so let's get to it.

Can you see the FOIL method being spread out here? Let's keep going.

Hope this helps, and let me know if I made a mistake! ^_^