(11/35-9/14)*21

To solve the expression \((\frac{11}{35} - \frac{9}{14}) \times 21\), we first need to perform the subtraction inside the parentheses.

1. Find a common denominator for the fractions \(\frac{11}{35}\) and \(\frac{9}{14}\). The least common multiple of 35 and 14 is 70.

2. Convert both fractions to have a denominator of 70:

   • For \(\frac{11}{35}\): \[ \frac{11}{35} = \frac{11 \times 2}{35 \times 2} = \frac{22}{70} \]
   • For \(\frac{9}{14}\): \[ \frac{9}{14} = \frac{9 \times 5}{14 \times 5} = \frac{45}{70} \]

3. Now we can subtract the two fractions: \[ \frac{22}{70} - \frac{45}{70} = \frac{22 - 45}{70} = \frac{-23}{70} \]

4. Next, multiply the result by 21: \[ \frac{-23}{70} \times 21 = \frac{-23 \times 21}{70} \]

5. Calculate \(-23 \times 21\): \[ -23 \times 21 = -483 \]

6. Now, we divide by 70: \[ \frac{-483}{70} \]

Thus, the final result is: \[ \frac{-483}{70} \text{ or } -6.9 \text{ (approximately)} \]