Subtract 21/28 from 7/20
7/20 - 21/28 is -2/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 28 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
7/20 = 7 × 7/20 × 7 = 49/140 - Likewise, for the 2nd fraction, since 28 × 5 = 140,
21/28 = 21 × 5/28 × 5 = 105/140 - Subtract the two like fractions:
49/140 - 105/140 = 49 - 105/140 = -56/140 - After reducing the fraction, the answer is -2/5
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