Subtract 7/15 from 21/54
21/54 - 7/15 is -7/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 15 is 270
Next, find the equivalent fraction of both fractional numbers with denominator 270 - For the 1st fraction, since 54 × 5 = 270,
21/54 = 21 × 5/54 × 5 = 105/270 - Likewise, for the 2nd fraction, since 15 × 18 = 270,
7/15 = 7 × 18/15 × 18 = 126/270 - Subtract the two like fractions:
105/270 - 126/270 = 105 - 126/270 = -21/270 - After reducing the fraction, the answer is -7/90
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