Subtract 50/70 from 21/45
21/45 - 50/70 is -26/105.
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,
21/45 = 21 × 14/45 × 14 = 294/630 - Likewise, for the 2nd fraction, since 70 × 9 = 630,
50/70 = 50 × 9/70 × 9 = 450/630 - Subtract the two like fractions:
294/630 - 450/630 = 294 - 450/630 = -156/630 - After reducing the fraction, the answer is -26/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45-50/70 21/90-50/70 63/45-50/70