Subtract 20/21 from 9/15
9/15 - 20/21 is -37/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
9/15 = 9 × 7/15 × 7 = 63/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
20/21 = 20 × 5/21 × 5 = 100/105 - Subtract the two like fractions:
63/105 - 100/105 = 63 - 100/105 = -37/105
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