Subtract 40/70 from 30/84
30/84 - 40/70 is -3/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 70 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
30/84 = 30 × 5/84 × 5 = 150/420 - Likewise, for the 2nd fraction, since 70 × 6 = 420,
40/70 = 40 × 6/70 × 6 = 240/420 - Subtract the two like fractions:
150/420 - 240/420 = 150 - 240/420 = -90/420 - After reducing the fraction, the answer is -3/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/84-40/70 30/84-80/70 90/84-40/70