Subtract 21/8 from 15/30
1st number: 15/30, 2nd number: 2 5/8
15/30 - 21/8 is -17/8.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 8 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
15/30 = 15 × 4/30 × 4 = 60/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
21/8 = 21 × 15/8 × 15 = 315/120 - Subtract the two like fractions:
60/120 - 315/120 = 60 - 315/120 = -255/120 - After reducing the fraction, the answer is -17/8
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