First estimate the answer. Then add to find the exact answer. Write exact answers in simplest form.

[tex]\[ 15 \frac{3}{4} + 10 \frac{2}{7} \][/tex]



Answer :

Let's solve the problem step by step.

### Step 1: Estimate the answer

To estimate the sum of the mixed numbers \( 15 \frac{3}{4} \) and \( 10 \frac{2}{7} \), we can round them to the nearest whole number:
- \( 15 \frac{3}{4} \) is close to 16.
- \( 10 \frac{2}{7} \) is close to 10.

So, an estimate for the sum is:
[tex]\[ 16 + 10 = 26 \][/tex]

### Step 2: Convert mixed numbers to improper fractions

For \( 15 \frac{3}{4} \):
- The whole number part is 15.
- The fractional part is \( \frac{3}{4} \).
- Convert to an improper fraction: \( 15 \times 4 + 3 = 60 + 3 = 63 \).
- So, \( 15 \frac{3}{4} = \frac{63}{4} \).

For \( 10 \frac{2}{7} \):
- The whole number part is 10.
- The fractional part is \( \frac{2}{7} \).
- Convert to an improper fraction: \( 10 \times 7 + 2 = 70 + 2 = 72 \).
- So, \( 10 \frac{2}{7} = \frac{72}{7} \).

### Step 3: Find a common denominator

The denominators are 4 and 7. The least common multiple (LCM) of 4 and 7 is 28.

### Step 4: Adjust the numerators

Convert the fractions to have a common denominator of 28:
- With \(\frac{63}{4}\):
[tex]\[ \frac{63 \times 7}{4 \times 7} = \frac{441}{28} \][/tex]

- With \(\frac{72}{7}\):
[tex]\[ \frac{72 \times 4}{7 \times 4} = \frac{288}{28} \][/tex]

### Step 5: Add the numerators

Add the numerators of the fractions:
[tex]\[ 441 + 288 = 729 \][/tex]

So, the result is:
[tex]\[ \frac{729}{28} \][/tex]

### Step 6: Simplify the fraction and convert back to a mixed number

1. Simplify the fraction:
- The greatest common divisor (GCD) of 729 and 28 is 1 (since they don't share any common factors other than 1), so the fraction is already in simplest form.

2. Convert to a mixed number:
- Divide 729 by 28 to find the whole number part:
[tex]\[ 729 \div 28 \approx 26. \][/tex]
- The remainder is \( 729 - (26 \times 28) = 729 - 728 = 1 \).

So, the mixed number is:
[tex]\[ 26 \frac{1}{28} \][/tex]

### Final Answer:

The exact sum of [tex]\( 15 \frac{3}{4} \)[/tex] and [tex]\( 10 \frac{2}{7} \)[/tex] is [tex]\( 26 \frac{1}{28} \)[/tex].

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