Subtract 63/84 from 18/40
18/40 - 63/84 is -3/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 84 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
18/40 = 18 × 21/40 × 21 = 378/840 - Likewise, for the 2nd fraction, since 84 × 10 = 840,
63/84 = 63 × 10/84 × 10 = 630/840 - Subtract the two like fractions:
378/840 - 630/840 = 378 - 630/840 = -252/840 - After reducing the fraction, the answer is -3/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/40-63/84 18/80-63/84 54/40-63/84 90/40-63/84