Subtract 72/70 from 9/90, Solve 9/90

Subtract 72/70 from 9/90

1^st number: 9/90, 2^nd number: 1 2/70

9/90 - 72/70 is -13/14.

Find the least common denominator or LCM of the two denominators:
LCM of 90 and 70 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 90 × 7 = 630,
9/90 = 9 × 7/90 × 7 = 63/630
Likewise, for the 2nd fraction, since 70 × 9 = 630,
72/70 = 72 × 9/70 × 9 = 648/630
Subtract the two like fractions:
63/630 - 648/630 = 63 - 648/630 = -585/630
After reducing the fraction, the answer is -13/14

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