How much was invested in each rate?

Question

you invested 10,000 in two accounts paying 7% and 9% annual interest,respectively if the total interest earned for the year was 880.How much was invested at each rate?  

Answer 1

let X= amt invested at 9% interest rate.

 

the amt invested @ 7% interest = (10000-x).

 

.09x + .07(10000-x) = 880

 

.09x + 700 -.07x = 880

 

.02x = 180

 

x= 9000  

 

9000 was invested at 9% and 1000 was invested at 7% interest rate.