Answer
${{\$}} 7000$ was invested and earned $ 14\%$ interest, and
${{\$}} 5000$ was invested at $ 6\%$ loss.
Work Step by Step
Let $ x $ = amount invested at $ 14\%$ interest.
Interest earned from the $ 14\%$ paying account = $0.14x $
The rest of the investment, $(12,000-x)$ "earns" $-6\%$, which equals $\qquad $
$-0.06(12,000-x)$
The sum of these amounts earned is ${{\$}} 620:$
$0.14x-0.06(12,000-x)=680$
$0.14x-720+0.06x=680$
$0.20x=680+720$
$0.2x=1400 \qquad $ ... multiply with $5$
$ x=7000$
So, ${{\$}} 7000$ was invested and earned $ 14\%$ interest, and
${{\$}} 5000$ was invested at $ 6\%$ loss.
