Subtract 90/20 from 21/28
1st number: 21/28, 2nd number: 4 10/20
21/28 - 90/20 is -15/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 20 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 20 × 7 = 140,
90/20 = 90 × 7/20 × 7 = 630/140 - Subtract the two like fractions:
105/140 - 630/140 = 105 - 630/140 = -525/140 - After reducing the fraction, the answer is -15/4
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