Subtract 70/40 from 18/21
1st number: 18/21, 2nd number: 1 30/40
18/21 - 70/40 is -25/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
18/21 = 18 × 40/21 × 40 = 720/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
70/40 = 70 × 21/40 × 21 = 1470/840 - Subtract the two like fractions:
720/840 - 1470/840 = 720 - 1470/840 = -750/840 - After reducing the fraction, the answer is -25/28
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