Subtract 80/90 from 21/30
21/30 - 80/90 is -17/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 30 × 3 = 90,
21/30 = 21 × 3/30 × 3 = 63/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
80/90 = 80 × 1/90 × 1 = 80/90 - Subtract the two like fractions:
63/90 - 80/90 = 63 - 80/90 = -17/90
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