Alejandra has $800 in her checking account. She wants to spend part of this money on a computer. She wants to have exactly $150 left in her checking account after buying the computer. Write an equation used to find c , the amount of money in dollars that Alejandra can spend on the computer.

800-650=150

Step-by-step explanation:

c is the aboumt of money she spends to get the computer

, 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