Subtract 21/18 from 21/40
1st number: 21/40, 2nd number: 1 3/18
21/40 - 21/18 is -77/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 18 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Likewise, for the 2nd fraction, since 18 × 20 = 360,
21/18 = 21 × 20/18 × 20 = 420/360 - Subtract the two like fractions:
189/360 - 420/360 = 189 - 420/360 = -231/360 - After reducing the fraction, the answer is -77/120
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