What is 8/28 plus 3/9? (Answer: 13/21)

Exact Answer

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Problem: What is 8/28 plus 3/9?
Formula / Expression: 8/28 + 3/9
Final Answer: 13/21
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 28 and 9 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 28 × 9 = 252.
Working: LCD(28, 9) = 252

Step 2: Convert to Equivalent Fractions with Common Denominator 252
Multiply the numerator and denominator of 8/28 by 9, and multiply the numerator and denominator of 3/9 by 28 so both fractions share the common base 252.
Working: 8 × 9/28 × 9 = 72/252 and 3 × 28/9 × 28 = 84/252

Step 3: Add the Numerators
Now add the numerators (72 + 84 = 156) and keep the common denominator 252 unchanged.
Working: 72 + 84/252 = 156/252

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 156 and 252, which is 12. Divide both the numerator and denominator by 12.
Working: 156 ÷ 12/252 ÷ 12 = 13/21

Step 5: Decimal & Percentage Representation
Dividing the numerator 13 by denominator 21 produces a repeating decimal (approximately 0.619048, or 61.9048%).
Working: 13 ÷ 21 = 0.619048 (61.9048%)

Key Values:
- Simplified Fraction: 13/21
- Mixed Number Form: 13/21
- Decimal Value: 0.619048
- Percentage: 61.9048%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-8-28-plus-3-9/
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8/28 + 3/9 = 13/21

Simplified Fraction

13/21

Mixed Number

Proper (13/21)

Decimal Value

0.619048

Percentage

61.9048%

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Step-by-Step Solution: 8/28 + 3/9

Step 1

Find the Least Common Denominator (LCD)

The denominators 28 and 9 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 28 × 9 = 252.

LCD(28, 9) = 252

Step 2

Convert to Equivalent Fractions with Common Denominator 252

Multiply the numerator and denominator of 8/28 by 9, and multiply the numerator and denominator of 3/9 by 28 so both fractions share the common base 252.

8 × 9/28 × 9 = 72/252 and 3 × 28/9 × 28 = 84/252

Step 3

Add the Numerators

Now add the numerators (72 + 84 = 156) and keep the common denominator 252 unchanged.

72 + 84/252 = 156/252

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 156 and 252, which is 12. Divide both the numerator and denominator by 12.

156 ÷ 12/252 ÷ 12 = 13/21

Step 5

Decimal & Percentage Representation

Dividing the numerator 13 by denominator 21 produces a repeating decimal (approximately 0.619048, or 61.9048%).

13 ÷ 21 = 0.619048 (61.9048%)

Visual Representation

The diagram below illustrates 8/28 plus 3/9 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`13/21`
Mixed Number Form	`13/21`
Decimal Form	`0.619048`
Percentage	`61.9048%`

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Frequently Asked Questions

What is 8/28 plus 3/9 as a fraction?

8/28 + 3/9 in simplest fraction form is 13/21.

What is 8/28 plus 3/9 as a decimal?

8/28 + 3/9 converted to a decimal is 0.619048.

What is 8/28 plus 3/9 as a percentage?

8/28 + 3/9 expressed as a percentage is 61.9048%.

Does 8/28 plus 3/9 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.619048...) because the denominator contains prime factors other than 2 and 5.