Subtract 30/70 from 20/72
20/72 - 30/70 is -19/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 70 is 2520
Next, find the equivalent fraction of both fractional numbers with denominator 2520 - For the 1st fraction, since 72 × 35 = 2520,
20/72 = 20 × 35/72 × 35 = 700/2520 - Likewise, for the 2nd fraction, since 70 × 36 = 2520,
30/70 = 30 × 36/70 × 36 = 1080/2520 - Subtract the two like fractions:
700/2520 - 1080/2520 = 700 - 1080/2520 = -380/2520 - After reducing the fraction, the answer is -19/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/72-30/70 20/72-60/70 60/72-30/70 20/72-90/70