Answers

Subtract 35/90 from 21/70

21/70 - 35/90 is -4/45.

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,
   21/70 = 21 × 9/70 × 9 = 189/630
3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
   35/90 = 35 × 7/90 × 7 = 245/630
4. Subtract the two like fractions:
   189/630 - 245/630 = 189 - 245/630 = -56/630
5. After reducing the fraction, the answer is -4/45

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