Subtract 7/8 from 21/30
21/30 - 7/8 is -7/40.
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,
21/30 = 21 × 4/30 × 4 = 84/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
7/8 = 7 × 15/8 × 15 = 105/120 - Subtract the two like fractions:
84/120 - 105/120 = 84 - 105/120 = -21/120 - After reducing the fraction, the answer is -7/40
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