OpenStax, Algebra and Trigonometry 2e §11.6 Solving Systems with Gaussian Elimination · Example 14 · Linear Algebra · Matrices
Applying 3 × 3 Matrices to Finance
Ava invests a total of $10,000 in three accounts, one paying 5% interest, another paying 8% interest, and the third paying 9% interest. The annual interest earned on the three investments last year was $770. The amount invested at 9% was twice the amount invested at 5%. How much was invested at each rate?
OpenStax, Algebra and Trigonometry 2e · §11.6 Solving Systems with Gaussian Elimination · Example 14
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