a jar contains 0.25 liter of apple juice and 0.30 liter of grape juice. melissa poured 0.75 liter of pineapple juice into the jar. she then drank 0.20 liter of the mixture.

part a: write an expression to represent the total amount of juice left in the jar. (5 points)

part b: identify which property is used in each step to simplify the expression.