What is 9/51 plus 6/21? (Answer: 55/119)

Exact Answer

==================================================
Problem: What is 9/51 plus 6/21?
Formula / Expression: 9/51 + 6/21
Final Answer: 55/119
==================================================

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 9/51 by 7, and multiply the numerator and denominator of 6/21 by 17 so both fractions share the common base 357.
Working: 9 × 7/51 × 7 = 63/357 and 6 × 17/21 × 17 = 102/357

Step 3: Add the Numerators
Now add the numerators (63 + 102 = 165) and keep the common denominator 357 unchanged.
Working: 63 + 102/357 = 165/357

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 165 and 357, which is 3. Divide both the numerator and denominator by 3.
Working: 165 ÷ 3/357 ÷ 3 = 55/119

Step 5: Decimal & Percentage Representation
Dividing the numerator 55 by denominator 119 produces a repeating decimal (approximately 0.462185, or 46.2185%).
Working: 55 ÷ 119 = 0.462185 (46.2185%)

Key Values:
- Simplified Fraction: 55/119
- Mixed Number Form: 55/119
- Decimal Value: 0.462185
- Percentage: 46.2185%

--------------------------------------------------
Solved with FractionsCalc:
https://fractionscalc.com/what-is-9-51-plus-6-21/
==================================================

9/51 + 6/21 = 55/119

Simplified Fraction

55/119

Mixed Number

Proper (55/119)

Decimal Value

0.462185

Percentage

46.2185%

Reduce / Convert Fraction:

Convert Fraction:

Enter Decimal Number:

Enter Percentage: %

What is % of

From Value: To Value:

Simplify Ratio: :

Switch to Proportion / Missing X Solver (A/B = C/D) →

Enter 3 known numbers and leave 1 empty (or type x) to solve:

← Switch to Ratio Simplifier (A:B)

Provide any 2 values below to calculate the remaining:

Price before discount

Discount

Price after discount

You saved

+ Add Sales Tax & Extra Coupon (Optional)

Sales Tax: % Extra Off: %

Provide any 2 values below to calculate the remaining:

Cost

Markup

REVENUE

Gross Profit

Profit Margin

Bill Subtotal

Tip Percentage

Split (People)

👥

Quick Tip:

Total Bill

Split Between

👥

Tip % (Optional)

Include Tip:

Total Price

Quantity

Unit of Measure

← Discount & Sales Tax • Ratio Simplifier (A:B) →

First Number: Second Number:

Find All Factors of:

Dividend: ÷ Divisor:

Number to Round: To Nearest:

Method: Standard (5+ ↑) Always Up (Ceil) Always Down (Floor)

Presets:

√ Square Root of: OR Power (x^y): ^{^}

x² + x + = 0

Number (n! & log):

Circle Radius (r):

Side a: Side b:

Angle (Degrees): °

Numbers (comma separated):

Total Items (n): Choose (r):

Decimal Number:

Number (1–3999):

Step-by-Step Solution: 9/51 + 6/21

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 9/51 by 7, and multiply the numerator and denominator of 6/21 by 17 so both fractions share the common base 357.

9 × 7/51 × 7 = 63/357 and 6 × 17/21 × 17 = 102/357

Step 3

Add the Numerators

Now add the numerators (63 + 102 = 165) and keep the common denominator 357 unchanged.

63 + 102/357 = 165/357

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 165 and 357, which is 3. Divide both the numerator and denominator by 3.

165 ÷ 3/357 ÷ 3 = 55/119

Step 5

Decimal & Percentage Representation

Dividing the numerator 55 by denominator 119 produces a repeating decimal (approximately 0.462185, or 46.2185%).

55 ÷ 119 = 0.462185 (46.2185%)

Visual Representation

The diagram below illustrates 9/51 plus 6/21 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`55/119`
Mixed Number Form	`55/119`
Decimal Form	`0.462185`
Percentage	`46.2185%`

Was this solution helpful?

Help us improve our free step-by-step tools

Frequently Asked Questions

What is 9/51 plus 6/21 as a fraction?

9/51 + 6/21 in simplest fraction form is 55/119.

What is 9/51 plus 6/21 as a decimal?

9/51 + 6/21 converted to a decimal is 0.462185.

What is 9/51 plus 6/21 as a percentage?

9/51 + 6/21 expressed as a percentage is 46.2185%.

Does 9/51 plus 6/21 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.462185...) because the denominator contains prime factors other than 2 and 5.