Subtract 21/40 from 16/45
16/45 - 21/40 is -61/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 45 × 8 = 360,
16/45 = 16 × 8/45 × 8 = 128/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Subtract the two like fractions:
128/360 - 189/360 = 128 - 189/360 = -61/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 32/45-21/40 16/45-42/40 16/90-21/40 16/45-21/80 48/45-21/40 16/45-63/40 80/45-21/40