Subtract 42/27 from 70/49, Solve 1 21/49

Subtract 42/27 from 70/49

1^st number: 1 21/49, 2^nd number: 1 15/27

70/49 - 42/27 is -8/63.

Find the least common denominator or LCM of the two denominators:
LCM of 49 and 27 is 1323

Next, find the equivalent fraction of both fractional numbers with denominator 1323
For the 1st fraction, since 49 × 27 = 1323,
70/49 = 70 × 27/49 × 27 = 1890/1323
Likewise, for the 2nd fraction, since 27 × 49 = 1323,
42/27 = 42 × 49/27 × 49 = 2058/1323
Subtract the two like fractions:
1890/1323 - 2058/1323 = 1890 - 2058/1323 = -168/1323
After reducing the fraction, the answer is -8/63

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