Question

Morgan needs to earn $16.31 more to have $40.00. Four students wrote and solved equations to find m, the amount of money that Morgan has now. Which student wrote and solved the equation correctly?
Sid’s work:
m minus 16 dollars and 31 cents = 40 dollars. M = 56 dollars and 31 cents.
Sora’s work:
m + 16 dollars and 31 cents = 40 dollars. M = 23 dollars and 69 cents.
Matt’s work:
16 dollars and 31 cents + 40 dollars = m. m = 56 dollars and 31 cents.
Zyad’s work:
16 dollars and 31 cents m = 40 dollars. M = 23 dollars and 69 cents.

Answer 1

To determine which student wrote and solved the equation correctly, let's analyze the problem.

Morgan needs to earn $16.31 more to have $40.00, which means:

\[ \text{Morgan's current amount (m)} + 16.31 = 40.00 \]

To find Morgan's current amount (m), we rearrange the equation:

\[ m = 40.00 - 16.31 \]

Now let's calculate:

\[ 40.00 - 16.31 = 23.69 \]

So, Morgan currently has $23.69.

Now let's evaluate each student's work:

1. **Sid’s work:**
- Equation: \( m - 16.31 = 40 \)
- Solving gives: \( m = 40 + 16.31 = 56.31 \) (Incorrect)

2. **Sora’s work:**
- Equation: \( m + 16.31 = 40 \)
- Solving gives: \( m = 40 - 16.31 = 23.69 \) (Correct)

3. **Matt’s work:**
- Equation: \( 16.31 + 40 = m \)
- Solving gives: \( m = 56.31 \) (Incorrect)

4. **Zyad’s work:**
- Equation: \( 16.31m = 40 \)
- Solving gives \( m = 40 / 16.31 \), which is not the correct approach. (Incorrect)

The only student who wrote and solved the equation correctly is **Sora**, who found that Morgan currently has $23.69.