Subtract 42/12 from 30/45
1st number: 30/45, 2nd number: 3 6/12
30/45 - 42/12 is -17/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 12 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
30/45 = 30 × 4/45 × 4 = 120/180 - Likewise, for the 2nd fraction, since 12 × 15 = 180,
42/12 = 42 × 15/12 × 15 = 630/180 - Subtract the two like fractions:
120/180 - 630/180 = 120 - 630/180 = -510/180 - After reducing the fraction, the answer is -17/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/45-42/12 30/45-84/12 30/90-42/12 30/45-42/24 90/45-42/12 30/45-42/36 30/45-42/60 30/45-42/84