400
Define variables, set-up the system. Do not solve:
You have 8,000 dollars to invest. You will put some in a low risk account earning 1%, and some in a high risk account claiming to earn 12%. How much should you put in each to earn $500 by the end of the year?
x= principle in low risk (1% account), y = principle in high risk (12% account), x + y = 8000, .01x+.12y = 500.
Note x = 1% is NOT acceptable. y = 12% is NOT acceptable.