Subtract 18/40 from 20/72
20/72 - 18/40 is -31/180.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
20/72 = 20 × 5/72 × 5 = 100/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
18/40 = 18 × 9/40 × 9 = 162/360 - Subtract the two like fractions:
100/360 - 162/360 = 100 - 162/360 = -62/360 - After reducing the fraction, the answer is -31/180
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