Subtract 30/8 from 15/42
1st number: 15/42, 2nd number: 3 6/8
15/42 - 30/8 is -95/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
15/42 = 15 × 4/42 × 4 = 60/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
30/8 = 30 × 21/8 × 21 = 630/168 - Subtract the two like fractions:
60/168 - 630/168 = 60 - 630/168 = -570/168 - After reducing the fraction, the answer is -95/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42-30/8 15/42-60/8 15/84-30/8 15/42-30/16 45/42-30/8 15/42-90/8 15/42-30/24 75/42-30/8 15/42-30/40 15/42-30/56