Subtract 9/20 from 21/14, Solve 1 7/14

Subtract 9/20 from 21/14

1^st number: 1 7/14, 2^nd number: 9/20

21/14 - 9/20 is 21/20.

Find the least common denominator or LCM of the two denominators:
LCM of 14 and 20 is 140

Next, find the equivalent fraction of both fractional numbers with denominator 140
For the 1st fraction, since 14 × 10 = 140,
21/14 = 21 × 10/14 × 10 = 210/140
Likewise, for the 2nd fraction, since 20 × 7 = 140,
9/20 = 9 × 7/20 × 7 = 63/140
Subtract the two like fractions:
210/140 - 63/140 = 210 - 63/140 = 147/140
After reducing the fraction, the answer is 21/20
In mixed form: 11/20

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