Subtract 90/70 from 20/12, Solve 1 8/12

Subtract 90/70 from 20/12

1^st number: 1 8/12, 2^nd number: 1 20/70

20/12 - 90/70 is 8/21.

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

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 12 × 35 = 420,
20/12 = 20 × 35/12 × 35 = 700/420
Likewise, for the 2nd fraction, since 70 × 6 = 420,
90/70 = 90 × 6/70 × 6 = 540/420
Subtract the two like fractions:
700/420 - 540/420 = 700 - 540/420 = 160/420
After reducing the fraction, the answer is 8/21

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