Pipe P can fill \( \frac{2}{9} \) part of a tank in 20 hours, and pipe Q can fill \( \frac{5}{9} \) part of the same tank in 10 hours. Both P and Q were kept open for 3 hours, then both were closed. Pipe R alone was then opened and it emptied the water in the tank in 8 hours. Pipes P, Q and R together can fill the empty tank in:
Simplify the following.
3((\( \frac{4}{3} \))x² - 21x + 12) - 4(x² + 4x - 14)
The value of 3² + \(\sqrt{4^2}\) - 5\(\sqrt{81}\) - 4 is