Subtract 45/10 from 21/72, Solve 21/72

Subtract 45/10 from 21/72

1^st number: 21/72, 2^nd number: 4 5/10

21/72 - 45/10 is -101/24.

Find the least common denominator or LCM of the two denominators:
LCM of 72 and 10 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 72 × 5 = 360,
21/72 = 21 × 5/72 × 5 = 105/360
Likewise, for the 2nd fraction, since 10 × 36 = 360,
45/10 = 45 × 36/10 × 36 = 1620/360
Subtract the two like fractions:
105/360 - 1620/360 = 105 - 1620/360 = -1515/360
After reducing the fraction, the answer is -101/24

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