Subtract 90/30 from 40/70
1st number: 40/70, 2nd number: 3 0/30
40/70 - 90/30 is -17/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
40/70 = 40 × 3/70 × 3 = 120/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
90/30 = 90 × 7/30 × 7 = 630/210 - Subtract the two like fractions:
120/210 - 630/210 = 120 - 630/210 = -510/210 - After reducing the fraction, the answer is -17/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/70-90/30 40/70-90/60