Subtract 21/7 from 15/20
1st number: 15/20, 2nd number: 3 0/7
15/20 - 21/7 is -9/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 7 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
15/20 = 15 × 7/20 × 7 = 105/140 - Likewise, for the 2nd fraction, since 7 × 20 = 140,
21/7 = 21 × 20/7 × 20 = 420/140 - Subtract the two like fractions:
105/140 - 420/140 = 105 - 420/140 = -315/140 - After reducing the fraction, the answer is -9/4
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