Subtract 9/20 from 2/21
2/21 - 9/20 is -149/420.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
2/21 = 2 × 20/21 × 20 = 40/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
9/20 = 9 × 21/20 × 21 = 189/420 - Subtract the two like fractions:
40/420 - 189/420 = 40 - 189/420 = -149/420
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