Subtract 20/21 from 30/36
30/36 - 20/21 is -5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 21 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 36 × 7 = 252,
30/36 = 30 × 7/36 × 7 = 210/252 - Likewise, for the 2nd fraction, since 21 × 12 = 252,
20/21 = 20 × 12/21 × 12 = 240/252 - Subtract the two like fractions:
210/252 - 240/252 = 210 - 240/252 = -30/252 - After reducing the fraction, the answer is -5/42
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