Subtract 18/36 from 21/90
21/90 - 18/36 is -4/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 36 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
21/90 = 21 × 2/90 × 2 = 42/180 - Likewise, for the 2nd fraction, since 36 × 5 = 180,
18/36 = 18 × 5/36 × 5 = 90/180 - Subtract the two like fractions:
42/180 - 90/180 = 42 - 90/180 = -48/180 - After reducing the fraction, the answer is -4/15
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