Write 2.5 repeating as a mixed number in simplest form.
The Correct Answer and Explanation is :
To convert the decimal (2.5) (which is (2.5) repeating) into a mixed number, we first represent it mathematically. The decimal (2.5) repeating can be expressed as (2.\overline{5}), where the digit (5) repeats indefinitely.
Step 1: Setting Up the Equation
Let (x = 2.\overline{5}). This means that:
[
x = 2.55555\ldots
]
Step 2: Eliminating the Repeating Decimal
To eliminate the repeating part, we can multiply (x) by (10) (since the repeating digit is in the tenths place):
[
10x = 25.55555\ldots
]
Now, we have two equations:
- (x = 2.55555\ldots)
- (10x = 25.55555\ldots)
Step 3: Subtracting the Two Equations
Now we subtract the first equation from the second:
[
10x – x = 25.55555\ldots – 2.55555\ldots
]
This simplifies to:
[
9x = 23
]
Step 4: Solving for (x)
Next, divide both sides by (9):
[
x = \frac{23}{9}
]
Step 5: Converting to Mixed Number
To convert the improper fraction (\frac{23}{9}) into a mixed number, we perform the division:
- Divide (23) by (9). The quotient is (2) (since (9 \times 2 = 18)).
- The remainder is (23 – 18 = 5).
Thus, we can express (\frac{23}{9}) as:
[
2 \frac{5}{9}
]
Conclusion
Therefore, the mixed number form of (2.5) repeating (or (2.\overline{5})) is:
[
2 \frac{5}{9}
]
This mixed number is in simplest form because (5) and (9) have no common factors other than (1).