Subtract 90/21 from 63/4, Solve 15 3/4

Subtract 90/21 from 63/4

1^st number: 15 3/4, 2^nd number: 4 6/21

63/4 - 90/21 is 321/28.

Find the least common denominator or LCM of the two denominators:
LCM of 4 and 21 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 4 × 21 = 84,
63/4 = 63 × 21/4 × 21 = 1323/84
Likewise, for the 2nd fraction, since 21 × 4 = 84,
90/21 = 90 × 4/21 × 4 = 360/84
Subtract the two like fractions:
1323/84 - 360/84 = 1323 - 360/84 = 963/84
After reducing the fraction, the answer is 321/28
In mixed form: 1113/28

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