Subtract 63/8 from 18/21
1st number: 18/21, 2nd number: 7 7/8
18/21 - 63/8 is -393/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
18/21 = 18 × 8/21 × 8 = 144/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
63/8 = 63 × 21/8 × 21 = 1323/168 - Subtract the two like fractions:
144/168 - 1323/168 = 144 - 1323/168 = -1179/168 - After reducing the fraction, the answer is -393/56
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