Question 908700
Don't waste your time nor our time writing this nonsense. 
The amount invested at 5% is?
The amount invested at 7% is?
It serves no useful purpose and it is annoying. Rather,spend time working on the problem.

Total amount of money invested: $40000
x+y=40000,
Total yearly interest for the two accounts is: $2280
0.05*x+0.07*y=2280
x=40000-y
Substitute for x
0.05*(40000-y)+0.07*y=2280
Multiply out
2000-0.05*y+0.07*y=2280
Combine like terms.
0.02*y=280
Isolate y
y=$14000.00 at 7%
x=40000-y
Calculate x
x=$26000.00 at 5%
Check
0.05*26000+0.07*14000=2280
1300+980=2280
2280=2280
If this statement is TRUE and neither x nor y  is negative then all is well