Subtract 20/21 from 25/40
25/40 - 20/21 is -55/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
25/40 = 25 × 21/40 × 21 = 525/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
20/21 = 20 × 40/21 × 40 = 800/840 - Subtract the two like fractions:
525/840 - 800/840 = 525 - 800/840 = -275/840 - After reducing the fraction, the answer is -55/168
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