What is 9/39 plus 6/21? (Answer: 47/91)

Exact Answer

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Problem: What is 9/39 plus 6/21?
Formula / Expression: 9/39 + 6/21
Final Answer: 47/91
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 39 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 273 (which is smaller than their product 39 × 21 = 819, keeping the calculation simpler).
Working: LCD(39, 21) = 273

Step 2: Convert to Equivalent Fractions with Common Denominator 273
Multiply the numerator and denominator of 9/39 by 7, and multiply the numerator and denominator of 6/21 by 13 so both fractions share the common base 273.
Working: 9 × 7/39 × 7 = 63/273 and 6 × 13/21 × 13 = 78/273

Step 3: Add the Numerators
Now add the numerators (63 + 78 = 141) and keep the common denominator 273 unchanged.
Working: 63 + 78/273 = 141/273

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 141 and 273, which is 3. Divide both the numerator and denominator by 3.
Working: 141 ÷ 3/273 ÷ 3 = 47/91

Step 5: Decimal & Percentage Representation
Dividing the numerator 47 by denominator 91 produces a repeating decimal (approximately 0.516484, or 51.6484%).
Working: 47 ÷ 91 = 0.516484 (51.6484%)

Key Values:
- Simplified Fraction: 47/91
- Mixed Number Form: 47/91
- Decimal Value: 0.516484
- Percentage: 51.6484%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-9-39-plus-6-21/
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9/39 + 6/21 = 47/91

Simplified Fraction

47/91

Mixed Number

Proper (47/91)

Decimal Value

0.516484

Percentage

51.6484%

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Step-by-Step Solution: 9/39 + 6/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 39 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 273 (which is smaller than their product 39 × 21 = 819, keeping the calculation simpler).

LCD(39, 21) = 273

Step 2

Convert to Equivalent Fractions with Common Denominator 273

Multiply the numerator and denominator of 9/39 by 7, and multiply the numerator and denominator of 6/21 by 13 so both fractions share the common base 273.

9 × 7/39 × 7 = 63/273 and 6 × 13/21 × 13 = 78/273

Step 3

Add the Numerators

Now add the numerators (63 + 78 = 141) and keep the common denominator 273 unchanged.

63 + 78/273 = 141/273

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 141 and 273, which is 3. Divide both the numerator and denominator by 3.

141 ÷ 3/273 ÷ 3 = 47/91

Step 5

Decimal & Percentage Representation

Dividing the numerator 47 by denominator 91 produces a repeating decimal (approximately 0.516484, or 51.6484%).

47 ÷ 91 = 0.516484 (51.6484%)

Visual Representation

The diagram below illustrates 9/39 plus 6/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`47/91`
Mixed Number Form	`47/91`
Decimal Form	`0.516484`
Percentage	`51.6484%`

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Frequently Asked Questions

What is 9/39 plus 6/21 as a fraction?

9/39 + 6/21 in simplest fraction form is 47/91.

What is 9/39 plus 6/21 as a decimal?

9/39 + 6/21 converted to a decimal is 0.516484.

What is 9/39 plus 6/21 as a percentage?

9/39 + 6/21 expressed as a percentage is 51.6484%.

Does 9/39 plus 6/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.516484...) because the denominator contains prime factors other than 2 and 5.