Subtract 7/21 from 9/30
9/30 - 7/21 is -1/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
9/30 = 9 × 7/30 × 7 = 63/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
7/21 = 7 × 10/21 × 10 = 70/210 - Subtract the two like fractions:
63/210 - 70/210 = 63 - 70/210 = -7/210 - After reducing the fraction, the answer is -1/30
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