Subtract 24/45 from 20/42
20/42 - 24/45 is -2/35.
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,
20/42 = 20 × 15/42 × 15 = 300/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
24/45 = 24 × 14/45 × 14 = 336/630 - Subtract the two like fractions:
300/630 - 336/630 = 300 - 336/630 = -36/630 - After reducing the fraction, the answer is -2/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-24/45 20/42-48/45 20/84-24/45 20/42-24/90 60/42-24/45 20/42-72/45