Subtract 90/70 from 7/30
1st number: 7/30, 2nd number: 1 20/70
7/30 - 90/70 is -221/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
7/30 = 7 × 7/30 × 7 = 49/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
90/70 = 90 × 3/70 × 3 = 270/210 - Subtract the two like fractions:
49/210 - 270/210 = 49 - 270/210 = -221/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/30-90/70 7/60-90/70 21/30-90/70 7/90-90/70 35/30-90/70 49/30-90/70