Final answer:
To calculate the participation grade (G) based on classes missed (M), the equation is G = 100 - 3M, with the grade starting at 100% and decreasing by 3% per missed class.
Step-by-step explanation:
To write an equation for computing the participation grade, G, as a function of the number of classes missed, M, we start with the understanding that the participation grade starts at 100%. The grade decreases by 3% for each missed class. Therefore, to calculate G, you can use the following equation:
G = 100 - 3M
This equation assumes that the grade cannot go below zero, and it translates to starting with a full grade of 100% and subtracting 3 percentage points for each class that the student misses.