Subtract 21/8 from 15/45, Solve 15/45

Subtract 21/8 from 15/45

1^st number: 15/45, 2^nd number: 2 5/8

15/45 - 21/8 is -55/24.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 8 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 45 × 8 = 360,
15/45 = 15 × 8/45 × 8 = 120/360
Likewise, for the 2nd fraction, since 8 × 45 = 360,
21/8 = 21 × 45/8 × 45 = 945/360
Subtract the two like fractions:
120/360 - 945/360 = 120 - 945/360 = -825/360
After reducing the fraction, the answer is -55/24

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