Subtract 45/40 from 12/42
1st number: 12/42, 2nd number: 1 5/40
12/42 - 45/40 is -47/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
12/42 = 12 × 20/42 × 20 = 240/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
45/40 = 45 × 21/40 × 21 = 945/840 - Subtract the two like fractions:
240/840 - 945/840 = 240 - 945/840 = -705/840 - After reducing the fraction, the answer is -47/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/42-45/40 12/42-90/40 12/84-45/40 12/42-45/80 36/42-45/40 60/42-45/40 84/42-45/40