Subtract 42/21 from 9/8
1st number: 1 1/8, 2nd number: 2 0/21
9/8 - 42/21 is -7/8.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
9/8 = 9 × 21/8 × 21 = 189/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
42/21 = 42 × 8/21 × 8 = 336/168 - Subtract the two like fractions:
189/168 - 336/168 = 189 - 336/168 = -147/168 - After reducing the fraction, the answer is -7/8
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