Solve the system of linear equations using matrices.

Question

A state government borrows $2,000,000 at simple annual interest. Some of the money is borrowed at 7%, some at 8.5%, and some at 9.5%. Use a system of linear equations to determine how much (in dollars) is borrowed at each rate given that the total annual interest is $161,250 and the amount borrowed at 8.5% is four times the amount borrowed at 9.5%. Solve the system of linear equations using matrices.

at 7% $ 

at 8.5% $

 at 9.5% $

Answer 1

a represents the amount at 9.5%

4a reepresents the amount at 8.5%

2000000 - 5a represents the amount at 7%

0.095a + 0.085(4a) + 0.07(2000000 - 5a) = 161250

Can you solve for a and answer?