Subtract 42/40 from 21/30
1st number: 21/30, 2nd number: 1 2/40
21/30 - 42/40 is -7/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 40 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 40 × 3 = 120,
42/40 = 42 × 3/40 × 3 = 126/120 - Subtract the two like fractions:
84/120 - 126/120 = 84 - 126/120 = -42/120 - After reducing the fraction, the answer is -7/20
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