Subtract 21/12 from 18/20
1st number: 18/20, 2nd number: 1 9/12
18/20 - 21/12 is -17/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 12 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 20 × 3 = 60,
18/20 = 18 × 3/20 × 3 = 54/60 - Likewise, for the 2nd fraction, since 12 × 5 = 60,
21/12 = 21 × 5/12 × 5 = 105/60 - Subtract the two like fractions:
54/60 - 105/60 = 54 - 105/60 = -51/60 - After reducing the fraction, the answer is -17/20
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