Jennifer invested $379 in a simple interest account. The account now has $554 in it. The money has been invested for 5 years. What interest rate (as a percentage) did this account have?

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  9.23%

Step-by-step explanation:

The account balance for simple interest is given by ...

  A = P(1 +rt) . . . . . principal P invested for t years at rate r

  554 = 379(1 +r·5)

  554 = 379 + 1895r . . . . eliminate parentheses

  175 = 1895r . . . . . . . . . subtract 379

  r = 175/1895 ≈ 0.092348 ≈ 9.23%

Jennifer's account had an interest rate of about 9.23%.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

, 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