Subtract 42/90 from 20/45
20/45 - 42/90 is -1/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 45 × 2 = 90,
20/45 = 20 × 2/45 × 2 = 40/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
42/90 = 42 × 1/90 × 1 = 42/90 - Subtract the two like fractions:
40/90 - 42/90 = 40 - 42/90 = -2/90 - After reducing the fraction, the answer is -1/45
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