Subtract 98/80 from 72/42, Solve 1 30/42

Subtract 98/80 from 72/42

1^st number: 1 30/42, 2^nd number: 1 18/80

72/42 - 98/80 is 137/280.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 42 × 40 = 1680,
72/42 = 72 × 40/42 × 40 = 2880/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
98/80 = 98 × 21/80 × 21 = 2058/1680
Subtract the two like fractions:
2880/1680 - 2058/1680 = 2880 - 2058/1680 = 822/1680
After reducing the fraction, the answer is 137/280

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