Subtract 30/8 from 18/21
1st number: 18/21, 2nd number: 3 6/8
18/21 - 30/8 is -81/28.
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,
30/8 = 30 × 21/8 × 21 = 630/168 - Subtract the two like fractions:
144/168 - 630/168 = 144 - 630/168 = -486/168 - After reducing the fraction, the answer is -81/28
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