Study the following chart and answer the question that follows.
The chart shows the quantity of substances (P1, P2, P3) in different drugs (A, B, C, D).
Which substance is/are most used in terms of quantity in all drugs?
Find the weighted arithmetic mean of the first 'n' natural numbers, the weights being the corresponding numbers.
\(\;\frac{n(n+1)(2n+1)}{6}\)
\(\;\frac{n(n+1)}{2}\)
\(\;\frac{2n+1}{3}\)
n
Simplify \(\frac{x^{2} + 2x + y^{2}}{x^{3} - 5x^{2}} \) If \(\; x + \frac{y^{2}}{x} = 5 \)
\(\tfrac{5}{y^{2}}\)
\(\tfrac{7}{y^{2}}\)
\(-\tfrac{5}{y^{2}}\)
\(-\tfrac{7}{y^{2}}\)