Subtract 30/42 from 18/70
18/70 - 30/42 is -16/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
18/70 = 18 × 3/70 × 3 = 54/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
30/42 = 30 × 5/42 × 5 = 150/210 - Subtract the two like fractions:
54/210 - 150/210 = 54 - 150/210 = -96/210 - After reducing the fraction, the answer is -16/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/70-30/42 18/70-60/42 18/70-30/84 54/70-30/42 18/70-90/42 90/70-30/42