Subtract 42/72 from 7/45
7/45 - 42/72 is -77/180.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 45 × 8 = 360,
7/45 = 7 × 8/45 × 8 = 56/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
42/72 = 42 × 5/72 × 5 = 210/360 - Subtract the two like fractions:
56/360 - 210/360 = 56 - 210/360 = -154/360 - After reducing the fraction, the answer is -77/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/45-42/72 7/45-84/72 7/90-42/72 21/45-42/72 35/45-42/72 49/45-42/72