Subtract 10/45 from 21/40
21/40 - 10/45 is 109/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 45 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 45 × 8 = 360,
10/45 = 10 × 8/45 × 8 = 80/360 - Subtract the two like fractions:
189/360 - 80/360 = 189 - 80/360 = 109/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/40-10/45 21/40-20/45 21/80-10/45 21/40-10/90 63/40-10/45 21/40-30/45 21/40-50/45 21/40-70/45