Subtract 9/42 from 21/36
21/36 - 9/42 is 31/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 42 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 36 × 7 = 252,
21/36 = 21 × 7/36 × 7 = 147/252 - Likewise, for the 2nd fraction, since 42 × 6 = 252,
9/42 = 9 × 6/42 × 6 = 54/252 - Subtract the two like fractions:
147/252 - 54/252 = 147 - 54/252 = 93/252 - After reducing the fraction, the answer is 31/84
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