Subtract 28/30 from 21/80
21/80 - 28/30 is -161/240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 30 is 240
Next, find the equivalent fraction of both fractional numbers with denominator 240 - For the 1st fraction, since 80 × 3 = 240,
21/80 = 21 × 3/80 × 3 = 63/240 - Likewise, for the 2nd fraction, since 30 × 8 = 240,
28/30 = 28 × 8/30 × 8 = 224/240 - Subtract the two like fractions:
63/240 - 224/240 = 63 - 224/240 = -161/240
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