Subtract 54/40 from 18/42
1st number: 18/42, 2nd number: 1 14/40
18/42 - 54/40 is -129/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
18/42 = 18 × 20/42 × 20 = 360/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
54/40 = 54 × 21/40 × 21 = 1134/840 - Subtract the two like fractions:
360/840 - 1134/840 = 360 - 1134/840 = -774/840 - After reducing the fraction, the answer is -129/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-54/40 18/84-54/40 18/42-54/80 54/42-54/40 90/42-54/40