Subtract 21/40 from 3/21
3/21 - 21/40 is -107/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
3/21 = 3 × 40/21 × 40 = 120/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Subtract the two like fractions:
120/840 - 441/840 = 120 - 441/840 = -321/840 - After reducing the fraction, the answer is -107/280
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