an investment is currently worth 2.125 × 10^4 dollars. ten years ago, the investment was worth 1.25 × 10^3…

Explanation:

Step1: Set up the division

Divide the current value by the past value. So we have $\frac{2.125\times 10^{4}}{1.25\times 10^{3}}$.

Step2: Separate the coefficients and exponents

Using the rule $\frac{a\times10^{m}}{b\times10^{n}}=\frac{a}{b}\times10^{m - n}$, we get $\frac{2.125}{1.25}\times10^{4 - 3}$.

Step3: Calculate the coefficient part

$\frac{2.125}{1.25}=1.7$.

Step4: Calculate the exponent part

$10^{4 - 3}=10^{1}=10$.

Step5: Multiply the results

$1.7\times10 = 17$.

Answer:

C. 17