Subtract 28/45 from 21/42
21/42 - 28/45 is -11/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 45 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 42 × 15 = 630,
21/42 = 21 × 15/42 × 15 = 315/630 - Likewise, for the 2nd fraction, since 45 × 14 = 630,
28/45 = 28 × 14/45 × 14 = 392/630 - Subtract the two like fractions:
315/630 - 392/630 = 315 - 392/630 = -77/630 - After reducing the fraction, the answer is -11/90
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