What is 4/9 plus 4/8? (Answer: 17/18)

Exact Answer

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Problem: What is 4/9 plus 4/8?
Formula / Expression: 4/9 + 4/8
Final Answer: 17/18
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Step-by-Step Solution:

Step 1: Find the Least Common Denominator (LCD)
The denominators 9 and 8 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 9 × 8 = 72.
Working: LCD(9, 8) = 72

Step 2: Convert to Equivalent Fractions with Common Denominator 72
Multiply the numerator and denominator of 4/9 by 8, and multiply the numerator and denominator of 4/8 by 9 so both fractions share the common base 72.
Working: 4 × 8/9 × 8 = 32/72 and 4 × 9/8 × 9 = 36/72

Step 3: Add the Numerators
Now add the numerators (32 + 36 = 68) and keep the common denominator 72 unchanged.
Working: 32 + 36/72 = 68/72

Step 4: Simplify the Fraction to Lowest Terms
Find the Greatest Common Divisor (GCD) of 68 and 72, which is 4. Divide both the numerator and denominator by 4.
Working: 68 ÷ 4/72 ÷ 4 = 17/18

Step 5: Decimal & Percentage Representation
Dividing the numerator 17 by denominator 18 produces a repeating decimal (approximately 0.944444, or 94.4444%).
Working: 17 ÷ 18 = 0.944444 (94.4444%)

Key Values:
- Simplified Fraction: 17/18
- Mixed Number Form: 17/18
- Decimal Value: 0.944444
- Percentage: 94.4444%

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Solved with FractionsCalc:
https://fractionscalc.com/what-is-4-9-plus-4-8/
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4/9 + 4/8 = 17/18

Simplified Fraction

17/18

Mixed Number

Proper (17/18)

Decimal Value

0.944444

Percentage

94.4444%

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Step-by-Step Solution: 4/9 + 4/8

Step 1

Find the Least Common Denominator (LCD)

The denominators 9 and 8 are coprime (they share no common factors other than 1). Therefore, their Least Common Denominator (LCD) is simply their direct product: 9 × 8 = 72.

LCD(9, 8) = 72

Step 2

Convert to Equivalent Fractions with Common Denominator 72

Multiply the numerator and denominator of 4/9 by 8, and multiply the numerator and denominator of 4/8 by 9 so both fractions share the common base 72.

4 × 8/9 × 8 = 32/72 and 4 × 9/8 × 9 = 36/72

Step 3

Add the Numerators

Now add the numerators (32 + 36 = 68) and keep the common denominator 72 unchanged.

32 + 36/72 = 68/72

Step 4

Simplify the Fraction to Lowest Terms

Find the Greatest Common Divisor (GCD) of 68 and 72, which is 4. Divide both the numerator and denominator by 4.

68 ÷ 4/72 ÷ 4 = 17/18

Step 5

Decimal & Percentage Representation

Dividing the numerator 17 by denominator 18 produces a repeating decimal (approximately 0.944444, or 94.4444%).

17 ÷ 18 = 0.944444 (94.4444%)

Visual Representation

The diagram below illustrates 4/9 plus 4/8 visually:

Summary & Alternative Representations

Property / Format	Value
Lowest Terms Fraction	`17/18`
Mixed Number Form	`17/18`
Decimal Form	`0.944444`
Percentage	`94.4444%`

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Frequently Asked Questions

What is 4/9 plus 4/8 as a fraction?

4/9 + 4/8 in simplest fraction form is 17/18.

What is 4/9 plus 4/8 as a decimal?

4/9 + 4/8 converted to a decimal is 0.944444.

What is 4/9 plus 4/8 as a percentage?

4/9 + 4/8 expressed as a percentage is 94.4444%.

Does 4/9 plus 4/8 result in a terminating or repeating decimal?

It results in a repeating decimal (approximately 0.944444...) because the denominator contains prime factors other than 2 and 5.