Subtract 1/42 from 21/45
21/45 - 1/42 is 31/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 42 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 45 × 14 = 630,
21/45 = 21 × 14/45 × 14 = 294/630 - Likewise, for the 2nd fraction, since 42 × 15 = 630,
1/42 = 1 × 15/42 × 15 = 15/630 - Subtract the two like fractions:
294/630 - 15/630 = 294 - 15/630 = 279/630 - After reducing the fraction, the answer is 31/70
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