How would we write an expression to show the number c being subtracted from the sum of a and b?
 start by writing an expression for "the sum of a and b."
 now, show c being subtracted from the sum.

a + b  - c

this is the answer... credit goes to Chris8799 under me he fixed my mistake

a + b - c

Step-by-step explanation:

Well think about it this way...

you can add those with no problem

The 16 oz jar

Step-by-step explanation:

12 oz jar

Cost = 8.65/12

Cost = $0.72/oz

16 oz jar

Cost = 10.99/16

Cost = $0.69/oz

24 oz jar

Cost = 16.99/24

Cost = $0.71/oz

The 16 oz jar costs less per ounce.