Subtract 98/80 from 7/21, Solve 7/21

Subtract 98/80 from 7/21

1^st number: 7/21, 2^nd number: 1 18/80

7/21 - 98/80 is -107/120.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 21 × 80 = 1680,
7/21 = 7 × 80/21 × 80 = 560/1680
Likewise, for the 2nd fraction, since 80 × 21 = 1680,
98/80 = 98 × 21/80 × 21 = 2058/1680
Subtract the two like fractions:
560/1680 - 2058/1680 = 560 - 2058/1680 = -1498/1680
After reducing the fraction, the answer is -107/120

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