Answer:
the answer is c!
Step-by-step explanation:
-21 + 28m = 8m + 19
20m = 40
m = 2
3x +x = 28
4x = 28
x = 28/4 = 7
7x3 = 21
Sari has 21 erasers
hope it is correct
i think it is more than, can , cannot, and required
