Please this is urgent please correct me in this. I will give you 5 stars

part a.  

.5x+3=18.5

part b.

.65x+3=21

part c.

in the explanation.

step-by-step explanation:

part a: she made 18.50.   she sold each cup for .50 and receive a 3 dollar tip.

we don't know how many cups she sold so i'm to call this x.

.5x is how much she made just on selling cups of lemonade.

she also got a 3 dollar tip in addition so that means we have .5x+3.   we are given that this amount should be 18.5 .

this means equation part part 1 should be .5x+3=18.5 .

part b.

she made a profit of 21.   she sold .75 per cup, and receive a 3 dollar tip. she also had to buy plastic cups for .1 each.

so let x represent the number of cups.

.75x is how much she made on lemonade

3 is how much she got extra

-.1x is how much she spent on each cup x.

adding that together gives:

.75x-.1x+3 and this amount is suppose to be 21 dollars.

.75x-.1x+3=21

we could simplify the equation a bit:

.65x+3=21

part c.

part a didn't include any money loss on the cups where as part b did.   they both got an extra 3 dollars from a neighbor.   daria still got more money per cup sold even after the loss of spending 10 cents per cup.