Subtract 21/12 from 42/40
1st number: 1 2/40, 2nd number: 1 9/12
42/40 - 21/12 is -7/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 12 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 40 × 3 = 120,
42/40 = 42 × 3/40 × 3 = 126/120 - Likewise, for the 2nd fraction, since 12 × 10 = 120,
21/12 = 21 × 10/12 × 10 = 210/120 - Subtract the two like fractions:
126/120 - 210/120 = 126 - 210/120 = -84/120 - After reducing the fraction, the answer is -7/10
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