Subtract 7/80 from 21/18, Solve 1 3/18

Subtract 7/80 from 21/18

1^st number: 1 3/18, 2^nd number: 7/80

21/18 - 7/80 is 259/240.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 80 is 720

Next, find the equivalent fraction of both fractional numbers with denominator 720
For the 1st fraction, since 18 × 40 = 720,
21/18 = 21 × 40/18 × 40 = 840/720
Likewise, for the 2nd fraction, since 80 × 9 = 720,
7/80 = 7 × 9/80 × 9 = 63/720
Subtract the two like fractions:
840/720 - 63/720 = 840 - 63/720 = 777/720
After reducing the fraction, the answer is 259/240
In mixed form: 119/240

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