A banker invested a portion of 10,000 at 5% interest per year and the remainder at 4% interest per year. If the banker received 470 in interest after one year how much was invested at each rate

Question

Should be self explanatory:)

Answer 1

x invested at 5% and y invested at 4%

x+y=10000

.05x+.04y=470 +> 5x+4y=47000

Multiply the first equation by5: 5x+5y=50000

Now subtract

y=3000

x=7000