QUESTION #3 is pictured BUT this is Question #5 in text. Refer back to Question #3. If Lili had invested her money in a CD in the 1980's (when CDs had
the highest rates in modern history) she could have received an interest rate of 11%. How
much more money would Lili have earned in the 1980's compared to now?

the correct answer is 45x

9×5=45 then add the x

, 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

6 and 24

step-by-step explanation:

6 x 4 = 24