Which bank checking account would be best for him to use if he wants to earn the most interest but knows he can only keep $200 in his account ?

, 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

1

x = 1

step-by-step explanation:

0 ÷ x = 0

0 ÷ 1 = 0