Subtract 70/90 from 21/30
21/30 - 70/90 is -7/90.
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,
70/90 = 70 × 1/90 × 1 = 70/90 - Subtract the two like fractions:
63/90 - 70/90 = 63 - 70/90 = -7/90
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