Subtract 72/40 from 7/90
1st number: 7/90, 2nd number: 1 32/40
7/90 - 72/40 is -31/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 90 × 4 = 360,
7/90 = 7 × 4/90 × 4 = 28/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
72/40 = 72 × 9/40 × 9 = 648/360 - Subtract the two like fractions:
28/360 - 648/360 = 28 - 648/360 = -620/360 - After reducing the fraction, the answer is -31/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-72/40 7/90-72/80 21/90-72/40 35/90-72/40 49/90-72/40