A diner makes vanilla milkshakes and chocolate milkshakes. The vanilla milkshake machine has a 300-cup capacity, and sells 15 cups per day. The chocolate milkshake machine has a 280-cup capacity, and sells 20 cups per day. Write an equation to show when the two machines will have the same amount of milkshake left.

Answer 1

Let's assume that after "x" days, the vanilla milkshake machine will have "V" cups left, and the chocolate milkshake machine will have "C" cups left.

The amount of vanilla milkshake left after "x" days can be calculated as:

V = 300 - 15x

The amount of chocolate milkshake left after "x" days can be calculated as:

C = 280 - 20x

To find when the two machines will have the same amount of milkshake left, we need to set V equal to C and solve for x:

300 - 15x = 280 - 20x

5x = 20

x = 4

Therefore, the two machines will have the same amount of milkshake left after 4 days.