Subtract 40/42 from 45/70
45/70 - 40/42 is -13/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
45/70 = 45 × 3/70 × 3 = 135/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
40/42 = 40 × 5/42 × 5 = 200/210 - Subtract the two like fractions:
135/210 - 200/210 = 135 - 200/210 = -65/210 - After reducing the fraction, the answer is -13/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/70-40/42 45/70-80/42 45/70-40/84