Question 6410
Hello,

The issue is setting the problem correctly. I tried it several times before I got it correct (with some help).

Step 1: Setup the problem
.135(x) + .09(5000-x) = 531

The way this is set up is to take the percentage, covert them to decimal, then multiple them by X. Except that one of the two must include 5000-x because that is the amount that was invested at the begining of the year subtracted from the orignal $5000. This equation is = to 531 because that is the profit received from the % of the two accounts. You don't use $5000 because that is the inital investment (this is where I messed up originally).

Step 2: Combine like terms
.135x + 450 - .090x = 531

Multiply .09 in to (5000-x) and then combine all values with X. You are left with what you see above.

Step 3: Solve for X
.045x = 81

Divide both sides by .045

x=81/.045 = $1800 at 13.5%

Since you set the problem up with 13.5% with X your solution ends up being X at 13.5%.

The remainder of the total amount is applied to (5000-x) at 9%

5000-x = $3200 at 9%

Hope this helps.

Thanks to R^2 for his assistance!