Question 793232
Louise splits an investment of $21000 , a portion earning simple interest at a rate of 4 % per year and the rest earning at a rate of 6.8 % per year in such a way that the return on the total investment is  5.96%. How much money was invested at a rate of 4% and a rate of 6.8%


$ x at 4%

$(21000-x) 6.8%

Total Interest = 5.96% of 21000

4%x+(21000-x)*6.8% = 5.96%*21000

multiply by 100

4x+6.8(21000-x) = 5.96*21000

4x+142800-6.8x =125160

-2.8x = 125160-142800

-2.8x =-17640
/-2.8

x=6300 at 4%

you can workout the other amount