Subtract 80/70 from 8/42, Solve 8/42

Subtract 80/70 from 8/42

1^st number: 8/42, 2^nd number: 1 10/70

8/42 - 80/70 is -20/21.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
8/42 = 8 × 5/42 × 5 = 40/210
Likewise, for the 2nd fraction, since 70 × 3 = 210,
80/70 = 80 × 3/70 × 3 = 240/210
Subtract the two like fractions:
40/210 - 240/210 = 40 - 240/210 = -200/210
After reducing the fraction, the answer is -20/21

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