Subtract 70/20 from 4/72, Solve 4/72

Subtract 70/20 from 4/72

1^st number: 4/72, 2^nd number: 3 10/20

4/72 - 70/20 is -31/9.

Find the least common denominator or LCM of the two denominators:
LCM of 72 and 20 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 72 × 5 = 360,
4/72 = 4 × 5/72 × 5 = 20/360
Likewise, for the 2nd fraction, since 20 × 18 = 360,
70/20 = 70 × 18/20 × 18 = 1260/360
Subtract the two like fractions:
20/360 - 1260/360 = 20 - 1260/360 = -1240/360
After reducing the fraction, the answer is -31/9

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