Respuesta :
Answer:
Step-by-step explanation:
The compound interest is represented by the following equation:
[tex]\begin{gathered} A=P(1+\frac{r}{n})^{nt} \\ \text{where}, \\ A=\text{ compound interest} \\ P=\text{ principal} \\ r=\text{ interest rate} \\ t=\text{time} \\ n=\text{times per year compounded} \end{gathered}[/tex]Therefore, for:
1. P=$4,000, t=7 years at r=6%
[tex]\begin{gathered} A=4000(1+0.06)^7 \\ A=\text{ \$6,014.52} \\ \\ \text{For the interest, subtract the principal amount:} \\ I=\text{ \$6,014.52}-\text{ \$4,000} \\ I=\text{ \$2,014.52} \end{gathered}[/tex]2. P= $5,000, t=20 years at r=5%
[tex]\begin{gathered} A=5000(1+0.05)^{20} \\ A=\text{ \$13,266.48} \\ \\ \text{For the interest, subtract the principal amount:} \\ I=\text{ \$13,266.48-\$5,000} \\ I=\text{ \$8,266.48} \end{gathered}[/tex]3. P=$700, t=15 years at 7%, n=2
[tex]\begin{gathered} A=700(1+\frac{0.07}{2})^15\cdot2 \\ A=1964.75 \\ \\ I=1964.75-700 \\ I=1264.75 \end{gathered}[/tex]