Subtract 4/9 from 21/49, Solve 21/49

Subtract 4/9 from 21/49

21/49 - 4/9 is -1/63.

Find the least common denominator or LCM of the two denominators:
LCM of 49 and 9 is 441

Next, find the equivalent fraction of both fractional numbers with denominator 441
For the 1st fraction, since 49 × 9 = 441,
21/49 = 21 × 9/49 × 9 = 189/441
Likewise, for the 2nd fraction, since 9 × 49 = 441,
4/9 = 4 × 49/9 × 49 = 196/441
Subtract the two like fractions:
189/441 - 196/441 = 189 - 196/441 = -7/441
After reducing the fraction, the answer is -1/63

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