Subtract 18/7 from 18/20
1st number: 18/20, 2nd number: 2 4/7
18/20 - 18/7 is -117/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 7 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
18/20 = 18 × 7/20 × 7 = 126/140 - Likewise, for the 2nd fraction, since 7 × 20 = 140,
18/7 = 18 × 20/7 × 20 = 360/140 - Subtract the two like fractions:
126/140 - 360/140 = 126 - 360/140 = -234/140 - After reducing the fraction, the answer is -117/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/20-18/7 18/20-36/7 18/40-18/7 18/20-18/14 54/20-18/7 18/20-54/7 18/60-18/7 18/20-18/21 90/20-18/7 18/20-90/7 18/20-18/35 18/20-18/49