Subtract 3/30 from 18/42
18/42 - 3/30 is 23/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
3/30 = 3 × 7/30 × 7 = 21/210 - Subtract the two like fractions:
90/210 - 21/210 = 90 - 21/210 = 69/210 - After reducing the fraction, the answer is 23/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-3/30 18/42-6/30 18/84-3/30 18/42-3/60 54/42-3/30 18/42-9/30 18/42-3/90 90/42-3/30 18/42-15/30 18/42-21/30