Answer:
Part A:

Part B:
15 people
Explanation:
Each person gets one club sandwich and two regular sandwiches. There is one additional Dagwood sandwich.
If a club sandwich has 3 slices, then the total amount of slices needed for
people will be
, since each person has 3 slices.
If a regular sandwich has 2 slices and everybody gets 2 regular sandwiches, then it's represented as
, since everyone has 4 slices each.
Additionally, we have one Dagwood sandwich, which can be represented as 5,, since a Dagwood sandwich has 5 slices.
Combining these terms we get
. Combining like terms gets us the expression
.
To solve for
, we have to make it an equation. Using the information in Part B, the Deli ends up receiving 110 slices of bread. So, the equation is

We want to isolate n on one side, to do this we have to subtract 5 then divide by 7.

So 15 people are going to the picnic.
Hope this helped!