Subtract 35/70 from 20/45
20/45 - 35/70 is -1/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 70 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 45 × 14 = 630,
20/45 = 20 × 14/45 × 14 = 280/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
35/70 = 35 × 9/70 × 9 = 315/630 - Subtract the two like fractions:
280/630 - 315/630 = 280 - 315/630 = -35/630 - After reducing the fraction, the answer is -1/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/45-35/70 20/90-35/70 60/45-35/70