Answers

Subtract 45/90 from 20/70

20/70 - 45/90 is -3/14.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 70 and 90 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 70 × 9 = 630,
   20/70 = 20 × 9/70 × 9 = 180/630
3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
   45/90 = 45 × 7/90 × 7 = 315/630
4. Subtract the two like fractions:
   180/630 - 315/630 = 180 - 315/630 = -135/630
5. After reducing the fraction, the answer is -3/14

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