Subtract 42/54 from 12/40
12/40 - 42/54 is -43/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 54 is 1080
Next, find the equivalent fraction of both fractional numbers with denominator 1080 - For the 1st fraction, since 40 × 27 = 1080,
12/40 = 12 × 27/40 × 27 = 324/1080 - Likewise, for the 2nd fraction, since 54 × 20 = 1080,
42/54 = 42 × 20/54 × 20 = 840/1080 - Subtract the two like fractions:
324/1080 - 840/1080 = 324 - 840/1080 = -516/1080 - After reducing the fraction, the answer is -43/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/40-42/54 12/40-84/54 12/80-42/54 36/40-42/54 60/40-42/54 84/40-42/54