To get ready for a new school year, meg 3 pens for $.79 each ,2notebooks for$1.29 each ,and 4 folders for $1.15 each. sales tax for all of the items was $.38 .how many change will meg get back from a$20?

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

Icould really use some with this question.

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.