200
y+x=20,000
0.05y+0.04x=850
y=-x+20,000
0.05y+0.04x=850
0.05(-x+20,000)+0.04x=850
x=15,000
$5,000 was invested in the 5% investment fund and $15,000 was invested in the 4% investment fund.
A total of $20,000 was invested in two annual investment funds. Fund Y paid 5% annual interest and fund X paid 4% annual interest. How much was invested in each fund if hte total interest for the year was $850?