Last year your town invested a total of $25,000 into two Separate funds. The return on one fund was 4% and the return on Te other fund was 6%. If the town earned a total of $1300 in interest, how much money was invested in each fund.

Sagot :

[tex]x-money\ the\ money\ that\ the\ town\ invested\ in\ fund\ \# 1\\y-money\ the\ money\ that\ the\ town\ invested\ in\ fund\ \#2\\4\%=0.04;\ 6\%=0.06\\\\ \left\{\begin{array}{ccc}x+y=25,000&|muliply\ both\ sides\ by\ (-4)\\0.04x+0.06y=1,300&|multiply\ both\ sides\ by\ 100\end{array}\right\\\\+\left\{\begin{array}{ccc}-4x-4y=-100,000\\4x+6y=130,000\end{array}\right\ |add\ the\ sides\ of\ the\ equations\\------------\\[/tex]
[tex].\ \ \ \ \ \ \ \ 2x=30,000\ \ \ \ \ |divide\ both\ sides\ by\ 2\\.\ \ \ \ \ \ \ \ \boxed{x=15,000}\\\\subtitute\ value\ of\ the\ x\ to\ equation\ x+y=25,000\\\\15,000+y=25,000\ \ \ \ \ \ |subtract\ 15,000\ from\ boths\ sides\\\boxed{x=10,000}\\\\Answer:\ The\ town\ invested\ \$15,000\ in\ found\ \#1\\and\ \$10,000\ in\ found\ \#2.[/tex]