Subtract 90/70 from 21/28
1st number: 21/28, 2nd number: 1 20/70
21/28 - 90/70 is -15/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 70 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
21/28 = 21 × 5/28 × 5 = 105/140 - Likewise, for the 2nd fraction, since 70 × 2 = 140,
90/70 = 90 × 2/70 × 2 = 180/140 - Subtract the two like fractions:
105/140 - 180/140 = 105 - 180/140 = -75/140 - After reducing the fraction, the answer is -15/28
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