Subtract 30/9 from 40/42
1st number: 40/42, 2nd number: 3 3/9
40/42 - 30/9 is -50/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 9 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
40/42 = 40 × 3/42 × 3 = 120/126 - Likewise, for the 2nd fraction, since 9 × 14 = 126,
30/9 = 30 × 14/9 × 14 = 420/126 - Subtract the two like fractions:
120/126 - 420/126 = 120 - 420/126 = -300/126 - After reducing the fraction, the answer is -50/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/42-30/9 40/42-60/9 40/84-30/9 40/42-30/18 40/42-90/9 40/42-30/27 40/42-30/45 40/42-30/63