Subtract 40/49 from 7/21
7/21 - 40/49 is -71/147.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 49 is 147
Next, find the equivalent fraction of both fractional numbers with denominator 147 - For the 1st fraction, since 21 × 7 = 147,
7/21 = 7 × 7/21 × 7 = 49/147 - Likewise, for the 2nd fraction, since 49 × 3 = 147,
40/49 = 40 × 3/49 × 3 = 120/147 - Subtract the two like fractions:
49/147 - 120/147 = 49 - 120/147 = -71/147
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