Kelly has 2 liters of milk in the refrigerator. She used 1/2 liter of milk in the morning with breakfast. She then used the same quantities of milk at both lunch and dinner, such that she used up all the milk. What quantity of milk did she use at dinner?

Cherie works in retail and her weekly salary includes commission for the amount she sells. the equation s=400+0.15c models the relation between her weekly salary, s, in dollars and the amount of her sales, c, in dollars. interpret the slope of the equation.