Subtract 27/40 from 9/42
9/42 - 27/40 is -129/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
9/42 = 9 × 20/42 × 20 = 180/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
27/40 = 27 × 21/40 × 21 = 567/840 - Subtract the two like fractions:
180/840 - 567/840 = 180 - 567/840 = -387/840 - After reducing the fraction, the answer is -129/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/42-27/40 9/42-54/40 9/84-27/40 9/42-27/80 27/42-27/40 9/42-81/40 45/42-27/40 63/42-27/40