Subtract 98/80 from 21/45, Solve 21/45

Subtract 98/80 from 21/45

1^st number: 21/45, 2^nd number: 1 18/80

21/45 - 98/80 is -91/120.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 80 is 720

Next, find the equivalent fraction of both fractional numbers with denominator 720
For the 1st fraction, since 45 × 16 = 720,
21/45 = 21 × 16/45 × 16 = 336/720
Likewise, for the 2nd fraction, since 80 × 9 = 720,
98/80 = 98 × 9/80 × 9 = 882/720
Subtract the two like fractions:
336/720 - 882/720 = 336 - 882/720 = -546/720
After reducing the fraction, the answer is -91/120

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