Subtract 20/45 from 5/21
5/21 - 20/45 is -13/63.
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,
5/21 = 5 × 15/21 × 15 = 75/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
20/45 = 20 × 7/45 × 7 = 140/315 - Subtract the two like fractions:
75/315 - 140/315 = 75 - 140/315 = -65/315 - After reducing the fraction, the answer is -13/63
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