Respuesta :
Answer:
- t + f = 20000
- 3%·t + 5%·f = 800
Step-by-step explanation:
Let t represent the amount invested at three percent; let f represent the amount invested at five percent. The total of these amounts is $20,000. The total of the interest earned by each amount is $800. Of course the interest earned is the amount multiplied by the interest rate.