Subtract 21/90 from 30/21, Solve 1 9/21

Subtract 21/90 from 30/21

1^st number: 1 9/21, 2^nd number: 21/90

30/21 - 21/90 is 251/210.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 21 × 30 = 630,
30/21 = 30 × 30/21 × 30 = 900/630
Likewise, for the 2nd fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630
Subtract the two like fractions:
900/630 - 147/630 = 900 - 147/630 = 753/630
After reducing the fraction, the answer is 251/210
In mixed form: 141/210

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