What is 4/35 plus 7/21? (Answer: 47/105)

Exact Answer

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Problem: What is 4/35 plus 7/21?
Formula / Expression: 4/35 + 7/21
Final Answer: 47/105
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 35 and 21 share a common factor (GCD = 7). Finding their Least Common Multiple gives an LCD of 105 (which is smaller than their product 35 × 21 = 735, keeping the calculation simpler).
Working: LCD(35, 21) = 105

Step 2: Convert to Equivalent Fractions with Common Denominator 105
Multiply the numerator and denominator of 4/35 by 3, and multiply the numerator and denominator of 7/21 by 5 so both fractions share the common base 105.
Working: 4 × 3/35 × 3 = 12/105 and 7 × 5/21 × 5 = 35/105

Step 3: Add the Numerators
Now add the numerators (12 + 35 = 47) and keep the common denominator 105 unchanged.
Working: 12 + 35/105 = 47/105

Step 4: Check if the Fraction Can Be Simplified
The Greatest Common Divisor (GCD) of 47 and 105 is 1, confirming that 47/105 cannot be reduced further—it is already in its simplest irreducible form.
Working: 47/105

Step 5: Decimal & Percentage Representation
Dividing the numerator 47 by denominator 105 produces a repeating decimal (approximately 0.447619, or 44.7619%).
Working: 47 ÷ 105 = 0.447619 (44.7619%)

Key Values:
- Simplified Fraction: 47/105
- Mixed Number Form: 47/105
- Decimal Value: 0.447619
- Percentage: 44.7619%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-4-35-plus-7-21/
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4/35 + 7/21 = 47/105

Simplified Fraction

47/105

Mixed Number

Proper (47/105)

Decimal Value

0.447619

Percentage

44.7619%

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Step-by-Step Solution: 4/35 + 7/21

Step 1

Find the Least Common Denominator (LCD)

The denominators 35 and 21 share a common factor (GCD = 7). Finding their Least Common Multiple gives an LCD of 105 (which is smaller than their product 35 × 21 = 735, keeping the calculation simpler).

LCD(35, 21) = 105

Step 2

Convert to Equivalent Fractions with Common Denominator 105

Multiply the numerator and denominator of 4/35 by 3, and multiply the numerator and denominator of 7/21 by 5 so both fractions share the common base 105.

4 × 3/35 × 3 = 12/105 and 7 × 5/21 × 5 = 35/105

Step 3

Add the Numerators

Now add the numerators (12 + 35 = 47) and keep the common denominator 105 unchanged.

12 + 35/105 = 47/105

Step 4

Check if the Fraction Can Be Simplified

The Greatest Common Divisor (GCD) of 47 and 105 is 1, confirming that 47/105 cannot be reduced further—it is already in its simplest irreducible form.

47/105

Step 5

Decimal & Percentage Representation

Dividing the numerator 47 by denominator 105 produces a repeating decimal (approximately 0.447619, or 44.7619%).

47 ÷ 105 = 0.447619 (44.7619%)

Visual Representation

The diagram below illustrates 4/35 plus 7/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`47/105`
Mixed Number Form	`47/105`
Decimal Form	`0.447619`
Percentage	`44.7619%`

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Frequently Asked Questions

What is 4/35 plus 7/21 as a fraction?

4/35 + 7/21 in simplest fraction form is 47/105.

What is 4/35 plus 7/21 as a decimal?

4/35 + 7/21 converted to a decimal is 0.447619.

What is 4/35 plus 7/21 as a percentage?

4/35 + 7/21 expressed as a percentage is 44.7619%.

Does 4/35 plus 7/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.447619...) because the denominator contains prime factors other than 2 and 5.