Solve each equation below for indicated variable a) am = n+p, for a

In terms of algebra, writing "am" is the same as writing "a*m" or "a times m"

To undo the multiplication, we use division. We will divide both sides by m to get 'a' all by itself on the left side

So...
am = n+p
a*m = n+p
(a*m)/m = (n+p)/m .... divide both sides by m
a = (n+p)/m ... notice how the 'm's cancel out when we divide on the left side

Final a = (n+p)/m
You must use parenthesis to indicate that all of "n+p" is over m or you can write it like this 

Where are the