Subtract 21/30 from 20/45
20/45 - 21/30 is -23/90.
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,
20/45 = 20 × 2/45 × 2 = 40/90 - Likewise, for the 2nd fraction, since 30 × 3 = 90,
21/30 = 21 × 3/30 × 3 = 63/90 - Subtract the two like fractions:
40/90 - 63/90 = 40 - 63/90 = -23/90
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