Subtract 15/20 from 21/30
21/30 - 15/20 is -1/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 20 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 30 × 2 = 60,
21/30 = 21 × 2/30 × 2 = 42/60 - Likewise, for the 2nd fraction, since 20 × 3 = 60,
15/20 = 15 × 3/20 × 3 = 45/60 - Subtract the two like fractions:
42/60 - 45/60 = 42 - 45/60 = -3/60 - After reducing the fraction, the answer is -1/20
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