Subtract 21/5 from 45/18
1st number: 2 9/18, 2nd number: 4 1/5
45/18 - 21/5 is -17/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 5 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 18 × 5 = 90,
45/18 = 45 × 5/18 × 5 = 225/90 - Likewise, for the 2nd fraction, since 5 × 18 = 90,
21/5 = 21 × 18/5 × 18 = 378/90 - Subtract the two like fractions:
225/90 - 378/90 = 225 - 378/90 = -153/90 - After reducing the fraction, the answer is -17/10
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