Subtract 72/40 from 18/84
1st number: 18/84, 2nd number: 1 32/40
18/84 - 72/40 is -111/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 84 × 10 = 840,
18/84 = 18 × 10/84 × 10 = 180/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
72/40 = 72 × 21/40 × 21 = 1512/840 - Subtract the two like fractions:
180/840 - 1512/840 = 180 - 1512/840 = -1332/840 - After reducing the fraction, the answer is -111/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/84-72/40 18/84-72/80 54/84-72/40 90/84-72/40