Subtract 7/90 from 21/49, Solve 21/49

Subtract 7/90 from 21/49

21/49 - 7/90 is 221/630.

Find the least common denominator or LCM of the two denominators:
LCM of 49 and 90 is 4410

Next, find the equivalent fraction of both fractional numbers with denominator 4410
For the 1st fraction, since 49 × 90 = 4410,
21/49 = 21 × 90/49 × 90 = 1890/4410
Likewise, for the 2nd fraction, since 90 × 49 = 4410,
7/90 = 7 × 49/90 × 49 = 343/4410
Subtract the two like fractions:
1890/4410 - 343/4410 = 1890 - 343/4410 = 1547/4410
After reducing the fraction, the answer is 221/630

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