Subtract 72/70 from 30/84, Solve 30/84

Subtract 72/70 from 30/84

1^st number: 30/84, 2^nd number: 1 2/70

30/84 - 72/70 is -47/70.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 70 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 84 × 5 = 420,
30/84 = 30 × 5/84 × 5 = 150/420
Likewise, for the 2nd fraction, since 70 × 6 = 420,
72/70 = 72 × 6/70 × 6 = 432/420
Subtract the two like fractions:
150/420 - 432/420 = 150 - 432/420 = -282/420
After reducing the fraction, the answer is -47/70

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