Question

Sara invested $8,000, part at 6% and the rest at 9% interest per year. How much did she invest at each rate if her total return per year on the investment was $660?

Answer 1

Set up a system of equations using the information you have. If you let X = the amount invested at 6% per year, and Y= the amount invested at 9% per year, then X+Y = 8000.

You can then set up the equation:
X*.06+Y*.09=660

From these, you should be able to solve for X and Y

Answer 2

I still don't get it.. @Vandreigan

Answer 3

You can solve one equation for one of the variables and sub it into the other equation, finding an actual value for the other variable.

For example, from X + Y = 8000 we get that X = 8000 - Y. Sub that in for X in the second equation and solve for Y.

Answer 4

Thank you :) @Vandreigan

Answer 5

My pleasure