Each deli sandwich made uses 1/4 pound of roast beef. Marisa started with 5 pounds of roast beef and now has 3/4 pounds left.

How many deli sandwiches did she make?

Let us assume the number of sandwiches made by Deli = x

Amount of roast beef required for making 1 sandwich = (1/4) pound

Total amount of beef that Marisa started with = 5 pounds

Amount of beef that was left = (3/4) pounds

Then

[ (1/4) * x] + (3/4) = 5

(x/4) + (3/4) = 5

(x + 3) / 4 = 5

x + 3 = 5 * 4

x + 3 = 20

x = 20 - 3

= 17

So we can see from the above deduction that 17 Deli sandwiches was made by Marisa. I hope the procedure is clear enough for you to understand.