1. ana was washing dishes at the end of her shift at a restaurant. she washed 30 plates from 7: 30 to 7: 35. when she finishes washing all the plates, her shift will end.

(a) if she started washing plates at 7: 15 and ended at 7: 38, estimate how many plates she washed in total. explain your reasoning.

(b) write an equation to represent how many plates ana has left to wash at a particular time after her start at 7: 15. explain your reasoning.

(A) If she started washing plates at 7:15 and ended at 7:38 she would have washed a total of 138 plates. Between 7:15 and 7:38 there is a difference of 28 minutes. If she washes 30 plates every 5 minutes, and 30 divided by 5 = 6, I know that she washes 6 plates per minute. 

Not sure what b is asking but this is what I understood
(b) 7:20 - 7:38= 18
18 times 6 = 108
If Ana started at 7:20, ended at 7:38, and she washes 6 dishes per minute, than she has 108 dishes left to wash.

If jon had $4.00 then takes away $2.25, then he should have $1.75 left. $4.00 - $2.25 = $1.75 hope this ; )