Subtract 72/80 from 20/42
20/42 - 72/80 is -89/210.
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,
20/42 = 20 × 40/42 × 40 = 800/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
72/80 = 72 × 21/80 × 21 = 1512/1680 - Subtract the two like fractions:
800/1680 - 1512/1680 = 800 - 1512/1680 = -712/1680 - After reducing the fraction, the answer is -89/210
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