Answer:
The expression is C/20 cups of flour in one cake
Step-by-step explanation:
* Lets explain how to solve the problem
- There are 10 students
- Each one made 2 chocolate cakes
- They all used the same recipe
- The total amount of flour is C cups
* Lets change these information to equation
∵ There are 10 students
∵ Each student made 2 cakes
∴ The total number of cakes = 10 × 2 = 20 cakes
∵ The total amount of flour for the twenty cakes is C cups
- To find the amount of flour in each cake divide the total amount
of flour by the total number of the cakes
∴ The amount of flour in each cake = C/20
* The expression is C/20 cups of flour in one cake
is the line 
. In general, any equation in the form 