Subtract 21/28 from 18/36
18/36 - 21/28 is -1/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 36 and 28 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 36 × 7 = 252,
18/36 = 18 × 7/36 × 7 = 126/252 - Likewise, for the 2nd fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252 - Subtract the two like fractions:
126/252 - 189/252 = 126 - 189/252 = -63/252 - After reducing the fraction, the answer is -1/4
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