# What is 20/15-9/21?

How much is 2015 minus 921. Step by step solution expressed as a proper or improper fraction, mixed number and decimal form.

• 1921
• 0.9048 (rounded to 4 decimals)

## Step by step solution

Subtract

2015 - 921 = 95105

1. ### Find common denominator by finding the Least Common Multiple(LCM)

Multiples of 15 are   15, 30, 45, 60, 75, 90, 105 ....etc

Multiples of 21 are   21, 42, 63, 84, 105 ...etc

The LCM of 15 and 21 is 105. So, the common denominator of 2015 and 921 is 105. Now change the fractions into equivalent fractions with common denominator

• 2015 - 921
• 20 * 715 * 7 - 9 * 521 * 5
• 140105 - 45105
2. ### Subtract

• 140105 - 45105
• 140 - 45105
• 95105

Subtract the numerators and place the difference over the common denominator.

Simplify

• 95105
• 1921
1. ### Reduce fraction to its lowest terms

• 95105
• 95 ÷ 5105 ÷ 5
• 1921

The greatest common divisor of 95 and 105 is 5, the fraction 95105 can be simplified or reduced to lowest terms by dividing the numerator and denominator by 5.