Subtract 21/8 from 42/18
1st number: 2 6/18, 2nd number: 2 5/8
42/18 - 21/8 is -7/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 8 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 18 × 4 = 72,
42/18 = 42 × 4/18 × 4 = 168/72 - Likewise, for the 2nd fraction, since 8 × 9 = 72,
21/8 = 21 × 9/8 × 9 = 189/72 - Subtract the two like fractions:
168/72 - 189/72 = 168 - 189/72 = -21/72 - After reducing the fraction, the answer is -7/24
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