Subtract 30/81 from 12/40
12/40 - 30/81 is -19/270.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
12/40 = 12 × 81/40 × 81 = 972/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
30/81 = 30 × 40/81 × 40 = 1200/3240 - Subtract the two like fractions:
972/3240 - 1200/3240 = 972 - 1200/3240 = -228/3240 - After reducing the fraction, the answer is -19/270
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/40-30/81 12/40-60/81 12/80-30/81 36/40-30/81 12/40-90/81 60/40-30/81 84/40-30/81