Subtract 18/20 from 7/9
7/9 - 18/20 is -11/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 9 × 20 = 180,
7/9 = 7 × 20/9 × 20 = 140/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
18/20 = 18 × 9/20 × 9 = 162/180 - Subtract the two like fractions:
140/180 - 162/180 = 140 - 162/180 = -22/180 - After reducing the fraction, the answer is -11/90
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