Subtract 72/80 from 30/40
30/40 - 72/80 is -3/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 80 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 40 × 2 = 80,
30/40 = 30 × 2/40 × 2 = 60/80 - Likewise, for the 2nd fraction, since 80 × 1 = 80,
72/80 = 72 × 1/80 × 1 = 72/80 - Subtract the two like fractions:
60/80 - 72/80 = 60 - 72/80 = -12/80 - After reducing the fraction, the answer is -3/20
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