Subtract 42/18 from 30/40
1st number: 30/40, 2nd number: 2 6/18
30/40 - 42/18 is -19/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 18 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
30/40 = 30 × 9/40 × 9 = 270/360 - Likewise, for the 2nd fraction, since 18 × 20 = 360,
42/18 = 42 × 20/18 × 20 = 840/360 - Subtract the two like fractions:
270/360 - 840/360 = 270 - 840/360 = -570/360 - After reducing the fraction, the answer is -19/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/40-42/18 30/40-84/18 30/80-42/18 30/40-42/36 90/40-42/18 30/40-42/54 30/40-42/90