You invested $7000 in two accounts paying 2% and 5% annual interest respectively. If the total interest earned was $230 how much was invested at each rate?

Question

anonymous · Answer

I posted this earlier but accidentally closed the question. I know that you have to set up a system of equations and then solve them but I cannot remember the process exactly. Any help would be much appreciated.

mertsj · Answer

.02x+.05(7000-x)=230

anonymous · Answer

I got that but I don't remember the full steps the the equations because you need more than one, don't you?

mertsj · Answer

You only have one variable so you can solve the equation.

mertsj · Answer

Multiply every term by 100 to get rid of the decimals.

anonymous · Answer

Wouldn't it be .02x+.05x=230 and then two other equations or am I over complicating it?

mertsj · Answer

So you are saying that he has equal amounts invested at the two different interest rates?

mertsj · Answer

And why, if you only have one variable, would you need three equations?

anonymous · Answer

I have no idea, I have been doing math for hours it is all blended together in my head now and nearly nothing makes sense anymore. I think i'm just over complicating it but all the other equations i have had to do like this are combined linear equations.

mertsj · Answer

If you want to use 2 variables you can.  Perhaps you will understand it better this way:
x+y=7000
.02x+.05y=230