Answer:
Step-by-step explanation:
The principal, P = $11000
m + n = 11000.................................(1)
Let the amount invested at 6% be m
interest at 6% = (m x 6 x 1)/100
Interest at 6% = 0.06m
Let the amount invested at 9% be n
interest at 9% = (m x 9 x 1)/100
Interest at 9% = 0.09n
Total interest = $870
0.06m + 0.09n = 870........................(2)
Multiply equation (1) by