ZOREH S. answered 07/11/22
CA Certified patient and knowledgeable Math Teacher, SAT / GRE Prep,
Lets X is the amount that is invested in 13% so the amount invested in -8% will be 18000 - X. We will find the total interest for each investment and put it equal to 765 then solve for x.
0.13 . X - 0 .08 ( 18000 - X ) = 765
0.13 X + 0.08 X = 765 + 1440
0.21 X = 2205
X = 10500 Dollars invested in 13% and 18000 - 10500 = $7500 was invested in -8% interest, meaning 8% loss.