# What is 12/7-9/21?

How much is 127 minus 921. Step by step solution expressed as a proper or improper fraction, mixed number and decimal form.

• 97
• 1 27
• 1.2857 (rounded to 4 decimals)

## Step by step solution

Subtract

127 - 921 = 2721

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

Multiples of 7 are   7, 14, 21 ....etc

Multiples of 21 are   21 ...etc

The LCM of 7 and 21 is 21. So, the common denominator of 127 and 921 is 21. Now change the fractions into equivalent fractions with common denominator

• 127 - 921
• 12 * 37 * 3 - 9 * 121 * 1
• 3621 - 921
2. ### Subtract

• 3621 - 921
• 36 - 921
• 2721

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

Simplify

• 2721
• 97
• 1 27
1. ### Reduce fraction to its lowest terms

• 2721
• 27 ÷ 321 ÷ 3
• 97

The greatest common divisor of 27 and 21 is 3, the fraction 2721 can be simplified or reduced to lowest terms by dividing the numerator and denominator by 3.

2. ### Convert improper fraction 97 to mixed number

• 97
• 1 27

9 divided by 7 is 1 with a remainder of 2