Subtract 27/30 from 21/45
21/45 - 27/30 is -13/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 30 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 45 × 2 = 90,
21/45 = 21 × 2/45 × 2 = 42/90 - Likewise, for the 2nd fraction, since 30 × 3 = 90,
27/30 = 27 × 3/30 × 3 = 81/90 - Subtract the two like fractions:
42/90 - 81/90 = 42 - 81/90 = -39/90 - After reducing the fraction, the answer is -13/30
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