Subtract 42/12 from 90/80, Solve 1 10/80

Subtract 42/12 from 90/80

1^st number: 1 10/80, 2^nd number: 3 6/12

90/80 - 42/12 is -19/8.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 12 is 240

Next, find the equivalent fraction of both fractional numbers with denominator 240
For the 1st fraction, since 80 × 3 = 240,
90/80 = 90 × 3/80 × 3 = 270/240
Likewise, for the 2nd fraction, since 12 × 20 = 240,
42/12 = 42 × 20/12 × 20 = 840/240
Subtract the two like fractions:
270/240 - 840/240 = 270 - 840/240 = -570/240
After reducing the fraction, the answer is -19/8

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