Subtract 98/40 from 72/84, Solve 72/84

Subtract 98/40 from 72/84

1^st number: 72/84, 2^nd number: 2 18/40

72/84 - 98/40 is -223/140.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 84 × 10 = 840,
72/84 = 72 × 10/84 × 10 = 720/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
98/40 = 98 × 21/40 × 21 = 2058/840
Subtract the two like fractions:
720/840 - 2058/840 = 720 - 2058/840 = -1338/840
After reducing the fraction, the answer is -223/140

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