For a school project, Tracy is investigating cell phone use in her hometown, Washington. So far, she has found that the residents of Washington used their cell phones for 179,580 minutes last year. This year, they used their cell phones for a total of 152,643 minutes. What is the percent of decrease in annual usage?

i think the correct option is the second option.

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for

i don't know, but that looks pretty bad. my school passed us unless we failed in all the subjects, but idk abt ur school's rules.

copyright potato 2019.

i honestly dont know