Subtract 18/20 from 30/70
30/70 - 18/20 is -33/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 70 × 2 = 140,
30/70 = 30 × 2/70 × 2 = 60/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
18/20 = 18 × 7/20 × 7 = 126/140 - Subtract the two like fractions:
60/140 - 126/140 = 60 - 126/140 = -66/140 - After reducing the fraction, the answer is -33/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/70-18/20 30/70-36/20 30/70-18/40 90/70-18/20 30/70-54/20 30/70-18/60 30/70-90/20