Final answer:
To solve for the amounts loaned at each interest rate, a system of linear equations is set up with two unknowns representing the amounts at 14% and 3% interest rates. By applying system-solving techniques, it was found that $3,500 was loaned at 14% interest and $16,500 at 3% interest.
Step-by-step explanation:
To determine how much was loaned at each interest rate given a total loan amount of $20,000 and a total interest of $985, we can set up a system of linear equations. Let's denote the amount loaned at 14% annual interest as x and the amount loaned at 3% annual interest as y. We have two conditions:
- The sum of the amounts loaned at both rates is $20,000: x + y = 20,000.
- The total interest from both loans is $985: 0.14x + 0.03y = 985.
We can use substitution or elimination to solve this system. If we subtract the second equation from the first one multiplied by 0.03, we eliminate y and can find the value of x. Then we can substitute the value of x back into any of the equations to find y.
Here's how the calculations would look:
- Multiply the first equation by 0.03: 0.03x + 0.03y = 600.
- Subtract this from the second equation: 0.14x - 0.03x + 0.03y - 0.03y = 985 - 600.
- Simplify and solve for x: 0.11x = 385, thus x = 385 / 0.11, which gives x = $3,500.
- Substitute x into the first equation: 3,500 + y = 20,000, thus y = 20,000 - 3,500, which gives y = $16,500.
So, $3,500 was loaned at 14%, and $16,500 was loaned at 3% annual interest.