Subtract 72/20 from 1/45
1st number: 1/45, 2nd number: 3 12/20
1/45 - 72/20 is -161/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
1/45 = 1 × 4/45 × 4 = 4/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
72/20 = 72 × 9/20 × 9 = 648/180 - Subtract the two like fractions:
4/180 - 648/180 = 4 - 648/180 = -644/180 - After reducing the fraction, the answer is -161/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/45-72/20 1/90-72/20 1/45-72/40 3/45-72/20 1/45-72/60 5/45-72/20 7/45-72/20