Subtract 21/5 from 12/20
1st number: 12/20, 2nd number: 4 1/5
12/20 - 21/5 is -18/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 5 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 20 × 1 = 20,
12/20 = 12 × 1/20 × 1 = 12/20 - Likewise, for the 2nd fraction, since 5 × 4 = 20,
21/5 = 21 × 4/5 × 4 = 84/20 - Subtract the two like fractions:
12/20 - 84/20 = 12 - 84/20 = -72/20 - After reducing the fraction, the answer is -18/5
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