Subtract 90/20 from 70/21
1st number: 3 7/21, 2nd number: 4 10/20
70/21 - 90/20 is -7/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
70/21 = 70 × 20/21 × 20 = 1400/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
90/20 = 90 × 21/20 × 21 = 1890/420 - Subtract the two like fractions:
1400/420 - 1890/420 = 1400 - 1890/420 = -490/420 - After reducing the fraction, the answer is -7/6
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