Question

Idk what to do.... please help!

Answer 1

The equation for the expression is M-4=A Because it says Amy is 4 years younger than Marty

Answer 2

Okay so Marty's age is m. That means we have NO IDEA how old he is. He could be 93 years old or 15 years old. We have no clue. Since he could be any number we will symbolize that number with m. Now it says that Amy is four years younger, this means we have to subtract 4 from any age that Marty is... 
this will give us: m-4
and that is your answer