Answer:
1. 6 should be added to both sides
2. f=19
Explanation:
When solving equations like this, we have to isolate the variable. To do this, perform the inverse operation to both sides of the equation.
-6+f=13
This can be rewritten as:
f-6=13
6 is being subtracted from f. In order to get f by itself, we have to get rid of the 6 being subtracted from f. The inverse of subtraction is addition. Add 6 to both sides.
f-6+6=13+6
f= 13+6
f=19