Subtract 90/7 from 18/80, Solve 18/80

Subtract 90/7 from 18/80

1^st number: 18/80, 2^nd number: 12 6/7

18/80 - 90/7 is -3537/280.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 7 is 560

Next, find the equivalent fraction of both fractional numbers with denominator 560
For the 1st fraction, since 80 × 7 = 560,
18/80 = 18 × 7/80 × 7 = 126/560
Likewise, for the 2nd fraction, since 7 × 80 = 560,
90/7 = 90 × 80/7 × 80 = 7200/560
Subtract the two like fractions:
126/560 - 7200/560 = 126 - 7200/560 = -7074/560
After reducing the fraction, the answer is -3537/280

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