Subtract 4/18 from 21/42
21/42 - 4/18 is 5/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
21/42 = 21 × 3/42 × 3 = 63/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
4/18 = 4 × 7/18 × 7 = 28/126 - Subtract the two like fractions:
63/126 - 28/126 = 63 - 28/126 = 35/126 - After reducing the fraction, the answer is 5/18
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