Subtract 70/49 from 7/90, Solve 7/90

Subtract 70/49 from 7/90

1^st number: 7/90, 2^nd number: 1 21/49

7/90 - 70/49 is -851/630.

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

Next, find the equivalent fraction of both fractional numbers with denominator 4410
For the 1st fraction, since 90 × 49 = 4410,
7/90 = 7 × 49/90 × 49 = 343/4410
Likewise, for the 2nd fraction, since 49 × 90 = 4410,
70/49 = 70 × 90/49 × 90 = 6300/4410
Subtract the two like fractions:
343/4410 - 6300/4410 = 343 - 6300/4410 = -5957/4410
After reducing the fraction, the answer is -851/630

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