intermediate algebra
posted by joel .
Select the set of equations that represents the following situation: Mike invested $706 for one year. He invested part of it at 5% and the rest at 3%. At the end of the year he earned $28.00 in interest. How much did Mike invest at each rate of interest?

x = amount invested at 0.05
y = amount invested at 0.03
0.05x + 0.03y = 28.
x + y = 706
Solve the set of equations simultaneously
If you are correct,
x = $341
y = $365 
solve. A trust fund has invested $8000 at 6% annual interest. How much additional moey should be invested at 8.5% to obtain a return of 8% on the total amount invested?