Subtract 49/42 from 21/20, Solve 1 1/20

Subtract 49/42 from 21/20

1^st number: 1 1/20, 2^nd number: 1 7/42

21/20 - 49/42 is -7/60.

Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420
Likewise, for the 2nd fraction, since 42 × 10 = 420,
49/42 = 49 × 10/42 × 10 = 490/420
Subtract the two like fractions:
441/420 - 490/420 = 441 - 490/420 = -49/420
After reducing the fraction, the answer is -7/60

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