Subtract 80/21 from 70/80
1st number: 70/80, 2nd number: 3 17/21
70/80 - 80/21 is -493/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
70/80 = 70 × 21/80 × 21 = 1470/1680 - Likewise, for the 2nd fraction, since 21 × 80 = 1680,
80/21 = 80 × 80/21 × 80 = 6400/1680 - Subtract the two like fractions:
1470/1680 - 6400/1680 = 1470 - 6400/1680 = -4930/1680 - After reducing the fraction, the answer is -493/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/80-80/42 70/80-80/63