Subtract 72/80 from 12/42
12/42 - 72/80 is -43/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 42 × 40 = 1680,
12/42 = 12 × 40/42 × 40 = 480/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
72/80 = 72 × 21/80 × 21 = 1512/1680 - Subtract the two like fractions:
480/1680 - 1512/1680 = 480 - 1512/1680 = -1032/1680 - After reducing the fraction, the answer is -43/70
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