Kelly is saving her money to buy a car. she has $250, and she plans to save $75 per week from her job as waitress.
a. model the situation using an arithmetic sequence.

b. how much will kelly have saved after 8 weeks?

c. if the car costs $2000, how long will it take her to save enough money at this rate?

someone me.

So she is essentially saving 250+n*75, where n is the number of weeks.

after 8 weeks she will have 250+8*75,  (you need to substitute n for the number of weeks, which is 8)

which is
250+600=850

how many more does she need for  a car?
she is still missing 2000-850, that is 1150. divide it by 75: it's a little more than 15: so she actually needs to save for 16 weeks after she's been saving for 8, that's a total of 24 weeks.

so in total it will take her 24 weeks (and she will have  a little extra).