Subtract 80/21 from 40/18, Solve 2 4/18

Subtract 80/21 from 40/18

1^st number: 2 4/18, 2^nd number: 3 17/21

40/18 - 80/21 is -100/63.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
40/18 = 40 × 7/18 × 7 = 280/126
Likewise, for the 2nd fraction, since 21 × 6 = 126,
80/21 = 80 × 6/21 × 6 = 480/126
Subtract the two like fractions:
280/126 - 480/126 = 280 - 480/126 = -200/126
After reducing the fraction, the answer is -100/63

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