Horrible lack of brackets.
There are no brackets, but follow the order of operations.
4x4=16
4x4=16
4x4=16
those are your multiplications.
16+16+4-16=20
Ah, Freelow, finally someone that sticks to order of operations. I swear to God, every time I see the infamous 2+2*2 and people say 8 I want to kill someone.