Subtract 21/40 from 7/18
7/18 - 21/40 is -49/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 18 × 20 = 360,
7/18 = 7 × 20/18 × 20 = 140/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
21/40 = 21 × 9/40 × 9 = 189/360 - Subtract the two like fractions:
140/360 - 189/360 = 140 - 189/360 = -49/360
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