Subtract 42/18 from 72/21
1st number: 3 9/21, 2nd number: 2 6/18
72/21 - 42/18 is 23/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
72/21 = 72 × 6/21 × 6 = 432/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
42/18 = 42 × 7/18 × 7 = 294/126 - Subtract the two like fractions:
432/126 - 294/126 = 432 - 294/126 = 138/126 - After reducing the fraction, the answer is 23/21
- In mixed form: 12/21
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