Angelo invested
$4,000
into two accounts. one account paid
4%
interest and the other paid
9%
interest. he earned
6%
interest on the total investment. how much money did he put in each account?

The amount invested in account that paid 4% was $2,400

The amount invested in account that paid 9% was $1.600

Step-by-step explanation:

Let

x -----> amount invested in account that paid 4%

(4,000-x) -----> amount invested in account that paid 9%

we know that

The linear equation that represent this scenario is

Solve for x

therefore

The amount invested in account that paid 4% was $2,400

The amount invested in account that paid 9% was $1.600

answerthe vertex form

step-by-step explanation:

, 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