Algebra
posted by Gman on .
Ernest receives $555 per year from his $7000 investment in municipal and corporate bonds. His municipal bonds pay 6% and his corporate bonds pay 9%. How much money is invested in each type of bond

Solve these two equations for M and C, the amounts invested in munis and corporates, respectivly.
M + C = 7000
0.06M + 0.09 C = 555
Using substitution,
0.06M + 0.09*(7000  M) = 555.
Rearranging the last equation,
0.03 M = 630  555 = 75
M = 75/0.03 = _____
C = 7000  M = ____ 
M=2,500
C=4,500