Subtract 42/12 from 21/45
1st number: 21/45, 2nd number: 3 6/12
21/45 - 42/12 is -91/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 12 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Likewise, for the 2nd fraction, since 12 × 15 = 180,
42/12 = 42 × 15/12 × 15 = 630/180 - Subtract the two like fractions:
84/180 - 630/180 = 84 - 630/180 = -546/180 - After reducing the fraction, the answer is -91/30
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