Question 6773
Well, you started out ok but when you got to the line: 8800 - x(.06) = 560, this is where your mistake lies.

It should have been:  (8800 - x)(.06) This is 6% of the total amount minus that invested at 7%
So, you should have:
 .07x + (8800 - x)(.06) = 560  Solve for x.
.07x + (.06)(8800) - .06x = 560 Simplify.
.07x - .06x + 528 = 560 
0.1x = 32
x = $3200 The amount invested at 7%