5. Ava invests \$12,000 in a Certificate of Deposit. She earns an annual simple interest rate of 7.15%. Which equation represents the total value of the investment, \( V \), after \( t \) years?

A. \( V = 12,000(0.0715) t \)

B. \( V = 12,000 + 12,000(0.0715) t \)

C. \( V = 12,000(0.715) t \)

D. [tex]\( V = 12,000 + 12,000(0.715) t \)[/tex]



Answer :

To determine which equation represents the total value of an investment with simple interest, we need to understand the formula for calculating simple interest. The formula for the total value, \( V \), of an investment with simple interest is:

[tex]\[ V = P + (P \cdot r \cdot t) \][/tex]

Where:
- \( P \) is the principal amount (the initial amount invested),
- \( r \) is the annual interest rate (expressed as a decimal),
- \( t \) is the time the money is invested for (in years).

Given:
- The principal amount, \( P \), is \$12,000.
- The annual interest rate, \( r \), is \(7.15\%\) or \(0.0715\) as a decimal.

Let's substitute these values into our formula:

[tex]\[ V = 12,000 + (12,000 \cdot 0.0715 \cdot t) \][/tex]

Simplify the expression inside the parentheses:

[tex]\[ V = 12,000 + 12,000(0.0715)t \][/tex]

This corresponds to option B. Therefore, the equation that represents the total value of Ava’s investment after \( t \) years is:

[tex]\[ V = 12,000 + 12,000(0.0715)t \][/tex]

Hence, the correct answer is B.