Answer:
y <= 20
Explanation:
Since it says a number y, our variable is y.
The number is multiplied by 5 which gives us 5y.
It is at most one hundred which means this is an inequality. It is AT MOST which means that 100 is a possible value. This means that our inequality is:
5y <= 100
Now we divide both sides by 5 to isolate y
y <= 20