Subtract 12/21 from 7/20
7/20 - 12/21 is -31/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
7/20 = 7 × 21/20 × 21 = 147/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
12/21 = 12 × 20/21 × 20 = 240/420 - Subtract the two like fractions:
147/420 - 240/420 = 147 - 240/420 = -93/420 - After reducing the fraction, the answer is -31/140
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