Finance (algebra)

[Tyler Durdan]

Assume, you put money into a savings account. The account earns simple interest, that is, it increases by a fixed amount each yr. After 2 years your account has 5,250 in it and after 5 years it has 6,375

Construct an equation to model the amount of money in your account
How much did you put in initally
How much will you have after 10 years


I am lost on this one people, it has been awhile, any comments are appeciated.

-Ty

 

[galactus]

Hello Tyler:

Simple interest is given by I=Prt.

So, if you subtract the principle P from the amount earned, 5250, you have

\(\displaystyle \L\\5250-P=2Pr\)

and

\(\displaystyle \L\\6375-P=5Pr\)

You have two equations with two variables. Can you solve?.

 

[TchrWill]

Assume, you put money into a savings account. The account earns simple interest, that is, it increases by a fixed amount each yr. After 2 years your account has 5,250 in it and after 5 years it has 6,375

Construct an equation to model the amount of money in your account
How much did you put in initally
How much will you have after 10 years

The way you worded the problem, it would appear that the key words are "fixed amount" which I take to mean a fixed $ amount.

If P is the starting amount, I is the fixed interest amount and S is the sum at the end ofeach year, you can write:

P + 5I = 6375 and P + 2I = 3250.

Subtracting will take you to the annual interest amount, I, and the starting amount,P.

The amount after 10 years would be S(10) = P + 10I.

 

[Tyler Durdan]

Thanks guys, I just worked it out from scratch using your information as a guideline and think I got it.

4500 was the inital amount and after 10 years it should be at 8250.



I am stuck on a few more but I am making good progress however I keep coming back to "Find the dimensions of a rectangle whose area is 240cm2 and perimeter is 62cm."

any ideas should I make a new post, I figured you all have been helpful here, I have tried setting it up various ways but my answer is always way off.

 

[galactus]

I am stuck on a few more but I am making good progress however I keep coming back to "Find the dimensions of a rectangle whose area is 240cm2 and perimeter is 62cm."

\(\displaystyle \L\\xy=240\)
\(\displaystyle \L\\2x+2y=62\)

Solve for x and y?.



any ideas should I make a new post, I figured you all have been helpful here, I have tried setting it up various ways but my answer is always way off.[/quote]