Subtract 21/7 from 18/20
1st number: 18/20, 2nd number: 3 0/7
18/20 - 21/7 is -21/10.
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,
18/20 = 18 × 7/20 × 7 = 126/140 - Likewise, for the 2nd fraction, since 7 × 20 = 140,
21/7 = 21 × 20/7 × 20 = 420/140 - Subtract the two like fractions:
126/140 - 420/140 = 126 - 420/140 = -294/140 - After reducing the fraction, the answer is -21/10
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