What is 4/51 plus 9/21? (Answer: 181/357)

Exact Answer

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Problem: What is 4/51 plus 9/21?
Formula / Expression: 4/51 + 9/21
Final Answer: 181/357
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 51 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 357 (which is smaller than their product 51 × 21 = 1071, keeping the calculation simpler).
Working: LCD(51, 21) = 357

Step 2: Convert to Equivalent Fractions with Common Denominator 357
Multiply the numerator and denominator of 4/51 by 7, and multiply the numerator and denominator of 9/21 by 17 so both fractions share the common base 357.
Working: 4 × 7/51 × 7 = 28/357 and 9 × 17/21 × 17 = 153/357

Step 3: Add the Numerators
Now add the numerators (28 + 153 = 181) and keep the common denominator 357 unchanged.
Working: 28 + 153/357 = 181/357

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 181 and 357 is 1, confirming that 181/357 cannot be reduced further—it is already in its simplest irreducible form.
Working: 181/357

Step 5: Decimal & Percentage Representation
Dividing the numerator 181 by denominator 357 produces a repeating decimal (approximately 0.507003, or 50.7003%).
Working: 181 ÷ 357 = 0.507003 (50.7003%)

Key Values:
- Simplified Fraction: 181/357
- Mixed Number Form: 181/357
- Decimal Value: 0.507003
- Percentage: 50.7003%

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Solved with FractionsCalc:
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4/51 + 9/21 = 181/357

Simplified Fraction

181/357

Mixed Number

Proper (181/357)

Decimal Value

0.507003

Percentage

50.7003%

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Step-by-Step Solution: 4/51 + 9/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 51 and 21 share a common factor (GCD = 3). Finding their Least Common Multiple gives an LCD of 357 (which is smaller than their product 51 × 21 = 1071, keeping the calculation simpler).

LCD(51, 21) = 357

Step 2

Convert to Equivalent Fractions with Common Denominator 357

Multiply the numerator and denominator of 4/51 by 7, and multiply the numerator and denominator of 9/21 by 17 so both fractions share the common base 357.

4 × 7/51 × 7 = 28/357 and 9 × 17/21 × 17 = 153/357

Step 3

Add the Numerators

Now add the numerators (28 + 153 = 181) and keep the common denominator 357 unchanged.

28 + 153/357 = 181/357

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 181 and 357 is 1, confirming that 181/357 cannot be reduced further—it is already in its simplest irreducible form.

181/357

Step 5

Decimal & Percentage Representation

Dividing the numerator 181 by denominator 357 produces a repeating decimal (approximately 0.507003, or 50.7003%).

181 ÷ 357 = 0.507003 (50.7003%)

Visual Representation

The diagram below illustrates 4/51 plus 9/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`181/357`
Mixed Number Form	`181/357`
Decimal Form	`0.507003`
Percentage	`50.7003%`

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Frequently Asked Questions

What is 4/51 plus 9/21 as a fraction?

4/51 + 9/21 in simplest fraction form is 181/357.

What is 4/51 plus 9/21 as a decimal?

4/51 + 9/21 converted to a decimal is 0.507003.

What is 4/51 plus 9/21 as a percentage?

4/51 + 9/21 expressed as a percentage is 50.7003%.

Does 4/51 plus 9/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.507003...) because the denominator contains prime factors other than 2 and 5.