To find out how much money Filipe borrowed, we can use the formula for simple interest:

$I = P \times r \times t$

where:

• $I$ is the total interest paid,
• $P$ is the principal amount (the amount of money borrowed),
• $r$ is the annual interest rate (in decimal form),
• $t$ is the time in years.

Given:

• $I = 2400$ (total interest paid),
• $r = 8\% = 0.08$ (annual interest rate in decimal),
• $t = 5$ years.

We need to solve for $P$ (the principal amount).

Plugging in the values we have:

$2400 = P \times 0.08 \times 5$

Simplify the equation:

$2400 = P \times 0.4$

To solve for $P$, divide both sides by 0.4:

$P = \frac{2400}{0.4}$

Calculating the division:

$P = 6000$

So, Filipe borrowed $6,000 from the credit union.

Do you want more details or have any questions?

Here are some related questions to consider:

1. What would the total interest be if the loan term was 3 years instead of 5 years?
2. How much would Filipe have borrowed if the interest rate was 5% instead of 8%?
3. If the interest rate is compounded annually instead of being simple interest, how would that affect the total interest paid?
4. What is the formula for compound interest, and how does it differ from simple interest?
5. How much would Filipe need to repay in total after 5 years, including both the principal and interest?

Tip: Always double-check the units of time and the format of the interest rate when applying formulas for financial calculations.