Subtract 70/18 from 16/21, Solve 16/21

Subtract 70/18 from 16/21

1^st number: 16/21, 2^nd number: 3 16/18

16/21 - 70/18 is -197/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 21 × 6 = 126,
16/21 = 16 × 6/21 × 6 = 96/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
70/18 = 70 × 7/18 × 7 = 490/126
Subtract the two like fractions:
96/126 - 490/126 = 96 - 490/126 = -394/126
After reducing the fraction, the answer is -197/63

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