What is 8/17 plus 9/13? (Answer: 257/221)

Exact Answer

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Problem: What is 8/17 plus 9/13?
Formula / Expression: 8/17 + 9/13
Final Answer: 1 36/221 (257/221)
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 17 and 13 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 17 × 13 = 221.
Working: LCD(17, 13) = 221

Step 2: Convert to Equivalent Fractions with Common Denominator 221
Multiply the numerator and denominator of 8/17 by 13, and multiply the numerator and denominator of 9/13 by 17 so both fractions share the common base 221.
Working: 8 × 13/17 × 13 = 104/221 and 9 × 17/13 × 17 = 153/221

Step 3: Add the Numerators
Now add the numerators (104 + 153 = 257) and keep the common denominator 221 unchanged.
Working: 104 + 153/221 = 257/221

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 257 and 221 is 1, confirming that 257/221 cannot be reduced further—it is already in its simplest irreducible form.
Working: 257/221

Step 5: Convert Improper Fraction to a Mixed Number
Since the numerator (257) is greater than the denominator (221), divide 257 by 221: it goes in 1 whole time(s) with a remainder of 36, giving the mixed number 1 36/221.
Working: 257/221 = 1 36/221

Step 6: Decimal & Percentage Representation
Dividing the numerator 257 by denominator 221 produces a repeating decimal (approximately 1.162896, or 116.2896%).
Working: 257 ÷ 221 = 1.162896 (116.2896%)

Key Values:
- Simplified Fraction: 257/221
- Mixed Number Form: 1 36/221
- Decimal Value: 1.162896
- Percentage: 116.2896%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-8-17-plus-9-13/
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8/17 + 9/13 = 257/221

Simplified Fraction

257/221

Mixed Number

1 36/221

Decimal Value

1.162896

Percentage

116.2896%

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Step-by-Step Solution: 8/17 + 9/13

Step 1

Find the Least Common Denominator (LCD)

The denominators 17 and 13 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 17 × 13 = 221.

LCD(17, 13) = 221

Step 2

Convert to Equivalent Fractions with Common Denominator 221

Multiply the numerator and denominator of 8/17 by 13, and multiply the numerator and denominator of 9/13 by 17 so both fractions share the common base 221.

8 × 13/17 × 13 = 104/221 and 9 × 17/13 × 17 = 153/221

Step 3

Add the Numerators

Now add the numerators (104 + 153 = 257) and keep the common denominator 221 unchanged.

104 + 153/221 = 257/221

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 257 and 221 is 1, confirming that 257/221 cannot be reduced further—it is already in its simplest irreducible form.

257/221

Step 5

Convert Improper Fraction to a Mixed Number

Since the numerator (257) is greater than the denominator (221), divide 257 by 221: it goes in 1 whole time(s) with a remainder of 36, giving the mixed number 1 36/221.

257/221 = 136/221

Step 6

Decimal & Percentage Representation

Dividing the numerator 257 by denominator 221 produces a repeating decimal (approximately 1.162896, or 116.2896%).

257 ÷ 221 = 1.162896 (116.2896%)

Visual Representation

The diagram below illustrates 8/17 plus 9/13 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`257/221`
Mixed Number Form	`1 36/221`
Decimal Form	`1.162896`
Percentage	`116.2896%`

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Frequently Asked Questions

What is 8/17 plus 9/13 as a fraction?

8/17 + 9/13 in simplest fraction form is 257/221 (or 1 36/221 as a mixed number).

What is 8/17 plus 9/13 as a decimal?

8/17 + 9/13 converted to a decimal is 1.162896.

What is 8/17 plus 9/13 as a percentage?

8/17 + 9/13 expressed as a percentage is 116.2896%.

How do you write 8/17 plus 9/13 as a mixed number?

Because the numerator is greater than the denominator, the improper fraction 257/221 can be written as the mixed number 1 36/221.

Does 8/17 plus 9/13 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 1.162896...) because the denominator contains prime factors other than 2 and 5.