Let x be the amount he invests at 6%
1280 = 0.06x + 0.07(20000 - x) 1280 = 0.06x + 1400 - 0.07x 1280 - 1400 = -0.01x -120 / -0.01 = x x = 12000
Therefore, he invests $12,000 at 6% and $8,000 at 7%
Mr. Jones's **investments **at 6% and 7% can be **calculated **by solving two linear equations representing the total amount invested and the total interest earned, respectively. ;
Mr. Jones invested $12,000 at 6% and $8,000 at 7%. This was determined by setting up and solving a system of equations based on the total investment and total interest earned. By substituting back into the original equations, we confirmed the amounts invested at each rate.
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