Subtract 30/45 from 8/42
8/42 - 30/45 is -10/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
8/42 = 8 × 15/42 × 15 = 120/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
30/45 = 30 × 14/45 × 14 = 420/630 - Subtract the two like fractions:
120/630 - 420/630 = 120 - 420/630 = -300/630 - After reducing the fraction, the answer is -10/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/42-30/45 8/42-60/45 8/84-30/45 8/42-30/90 24/42-30/45 8/42-90/45 40/42-30/45 56/42-30/45