Subtract 45/12 from 7/70, Solve 7/70

Subtract 45/12 from 7/70

1^st number: 7/70, 2^nd number: 3 9/12

7/70 - 45/12 is -73/20.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 12 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 70 × 6 = 420,
7/70 = 7 × 6/70 × 6 = 42/420
Likewise, for the 2nd fraction, since 12 × 35 = 420,
45/12 = 45 × 35/12 × 35 = 1575/420
Subtract the two like fractions:
42/420 - 1575/420 = 42 - 1575/420 = -1533/420
After reducing the fraction, the answer is -73/20

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