How many 1/2 liter of bottles of lemonade can you fo from 2 1/2 ft container

Me because some of question i don’t understand

Oliver had $50 on the day before his birthday. after he recived some money for his birthday , he had $75. write and solve eqaution to find how much money oliver received for his birthday. x+50=75

Which is an equivalent equation solved for r? the circumference of a circle can be found using the formula c = 2πr. r=cπ r=c(2π) r= c over 2π r= 2π over c