Answer :
- Determine the factor by which the numerator was multiplied: $39 = 3 \times 13$.
- Multiply the denominator by the same factor: $15 \times 3 = 45$.
- The equivalent fraction is $\frac{39}{45}$.
- The missing denominator is $\boxed{45}$.
### Explanation
1. Understanding the Problem
We are given the fraction $\frac{13}{15}$ and asked to find an equivalent fraction with a numerator of 39. Let the missing denominator be $x$. So, we have $\frac{13}{15} = \frac{39}{x}$.
2. Finding the Multiplication Factor
To find the equivalent fraction, we need to determine what factor we multiplied the numerator 13 by to get 39. Since $39 = 3 \times 13$, we multiplied the numerator by 3.
3. Multiplying the Denominator
To maintain the equality of the fractions, we must also multiply the denominator by the same factor. So, we multiply the denominator 15 by 3: $15 \times 3 = 45$.
4. Finding the Missing Denominator
Therefore, the equivalent fraction is $\frac{39}{45}$. The missing denominator is 45.
5. Final Answer
Thus, the complete equivalent fraction is $\frac{13}{15} = \frac{39}{45}$.
### Examples
Fractions are used in everyday life, such as when cooking, measuring ingredients, or calculating proportions. For example, if a recipe calls for $\frac{1}{3}$ cup of flour and you want to double the recipe, you need to multiply the fraction by 2. Understanding equivalent fractions helps in scaling recipes, adjusting measurements, and understanding proportions in various real-life situations.
- Multiply the denominator by the same factor: $15 \times 3 = 45$.
- The equivalent fraction is $\frac{39}{45}$.
- The missing denominator is $\boxed{45}$.
### Explanation
1. Understanding the Problem
We are given the fraction $\frac{13}{15}$ and asked to find an equivalent fraction with a numerator of 39. Let the missing denominator be $x$. So, we have $\frac{13}{15} = \frac{39}{x}$.
2. Finding the Multiplication Factor
To find the equivalent fraction, we need to determine what factor we multiplied the numerator 13 by to get 39. Since $39 = 3 \times 13$, we multiplied the numerator by 3.
3. Multiplying the Denominator
To maintain the equality of the fractions, we must also multiply the denominator by the same factor. So, we multiply the denominator 15 by 3: $15 \times 3 = 45$.
4. Finding the Missing Denominator
Therefore, the equivalent fraction is $\frac{39}{45}$. The missing denominator is 45.
5. Final Answer
Thus, the complete equivalent fraction is $\frac{13}{15} = \frac{39}{45}$.
### Examples
Fractions are used in everyday life, such as when cooking, measuring ingredients, or calculating proportions. For example, if a recipe calls for $\frac{1}{3}$ cup of flour and you want to double the recipe, you need to multiply the fraction by 2. Understanding equivalent fractions helps in scaling recipes, adjusting measurements, and understanding proportions in various real-life situations.
