Subtract 3/45 from 20/21
20/21 - 3/45 is 31/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
20/21 = 20 × 15/21 × 15 = 300/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
3/45 = 3 × 7/45 × 7 = 21/315 - Subtract the two like fractions:
300/315 - 21/315 = 300 - 21/315 = 279/315 - After reducing the fraction, the answer is 31/35
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