Subtract 18/20 from 12/28
12/28 - 18/20 is -33/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
12/28 = 12 × 5/28 × 5 = 60/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
18/20 = 18 × 7/20 × 7 = 126/140 - Subtract the two like fractions:
60/140 - 126/140 = 60 - 126/140 = -66/140 - After reducing the fraction, the answer is -33/70
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