Subtract 15/90 from 21/80
21/80 - 15/90 is 23/240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
21/80 = 21 × 9/80 × 9 = 189/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
15/90 = 15 × 8/90 × 8 = 120/720 - Subtract the two like fractions:
189/720 - 120/720 = 189 - 120/720 = 69/720 - After reducing the fraction, the answer is 23/240
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