Subtract 21/27 from 28/70
28/70 - 21/27 is -17/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 27 is 1890
Next, find the equivalent fraction of both fractional numbers with denominator 1890 - For the 1st fraction, since 70 × 27 = 1890,
28/70 = 28 × 27/70 × 27 = 756/1890 - Likewise, for the 2nd fraction, since 27 × 70 = 1890,
21/27 = 21 × 70/27 × 70 = 1470/1890 - Subtract the two like fractions:
756/1890 - 1470/1890 = 756 - 1470/1890 = -714/1890 - After reducing the fraction, the answer is -17/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/70-21/27 28/70-42/27 28/70-21/54 84/70-21/27 28/70-63/27 28/70-21/81