The number 'a' represents the number of accounts held in a large advertising firm. The number grows according to the rule a=75+3t (the 't' is raised) where 't' is the number of years from the year 2010.
\(a=75+3^t\)
a) How many accounts did the firm have in the year 2010
t=0
\(a=75+3^0=75\)
In 2010 there were 75 accounts
b) How many accounts were there in 2015
t=5
\(a=75+3^5=75+243=318\)
c) How many years will it take for the number of accounts to exceed 1000?
\(75+3^t>1000\\ 75-75+3^t>1000-75\\ 3^t>925\\ 3^6=729\qquad 3^7=2187\\ \mbox{925 will be exceeded in the 7th year}\\ \)
You can do this last question with logs but there was really no need to here because the answer was so little.
btw, I DO NOT want you to tell me the answer; only to give me clues or bits for me to figure out for myself or simply break down the worded questions for me. Thanks :)
Sorry, I didn't see your instruction until I had nearly finished. ://