Subtract 21/9 from 12/7
1st number: 1 5/7, 2nd number: 2 3/9
12/7 - 21/9 is -13/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 7 × 9 = 63,
12/7 = 12 × 9/7 × 9 = 108/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
21/9 = 21 × 7/9 × 7 = 147/63 - Subtract the two like fractions:
108/63 - 147/63 = 108 - 147/63 = -39/63 - After reducing the fraction, the answer is -13/21
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