Help? Can you guys tell me where to put it?

Mp model with mathematics explain how the number of text messages dario sent and the cost form an arithmetic sequence.then write an expression to find dario's text messaging bill if he sends n text messages over 250.

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.

Atown has a population of 12000 and grows at 3.5% every year. what will be the population after 7 years, to the nearest whole number?