Subtract 72/18 from 2/20, Solve 2/20

Subtract 72/18 from 2/20

1^st number: 2/20, 2^nd number: 4 0/18

2/20 - 72/18 is -39/10.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 18 is 180

Next, find the equivalent fraction of both fractional numbers with denominator 180
For the 1st fraction, since 20 × 9 = 180,
2/20 = 2 × 9/20 × 9 = 18/180
Likewise, for the 2nd fraction, since 18 × 10 = 180,
72/18 = 72 × 10/18 × 10 = 720/180
Subtract the two like fractions:
18/180 - 720/180 = 18 - 720/180 = -702/180
After reducing the fraction, the answer is -39/10

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