Subtract 18/20 from 21/7
1st number: 3 0/7, 2nd number: 18/20
21/7 - 18/20 is 21/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 7 × 20 = 140,
21/7 = 21 × 20/7 × 20 = 420/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
18/20 = 18 × 7/20 × 7 = 126/140 - Subtract the two like fractions:
420/140 - 126/140 = 420 - 126/140 = 294/140 - After reducing the fraction, the answer is 21/10
- In mixed form: 21/10
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