Answer:
f(r) = r + 12
Step-by-step explanation:
An expression is an equation that usually involves x and y. When we are dealing with a unknown number we use a variable. some common variable is x and y, in this instance we will use r. Therefore we have to have r in our expression. however, we need a output therefore we use function of r. (f(r))
p.s. F(r) usually represents y.
futhermore, if you see more than you know you will use addition.
hope this helps!
