How do you write one fifth of g is subtracted from 3?

3 - (1/5) * g

Step-by-step explanation:

One-fifth of "g" is taking the "whole" "g" and diving it by five (it could also be written as (g/5)). Subtract from 3 implies that the "3" is the starting value and and that you're subtracting one-fifth of g from that 3.