Winston hada test average of 86.2 last semester. His first four test grades were \( 81,88,93 \), and 77 . Use the formula \( \bar{x}=\frac{x_{1}+x_{2}+\ldots+x_{n}}{n} \) to find his score on the fifth test.

\begin{tabular}{l} B) DIRECTIONS: Solve each equation using the QUADRATIC FORMULA: \( x= \) \\ \( \qquad \)\begin{tabular}{|l|l|l}\hline 5\( ] c^{2}-5 c+4=0 \) & \( 6] b^{2}-b-12=0 \) & \( 73 a^{2}-4 a-12=0 \) \\ \hline\end{tabular} \\ \hline\end{tabular}

Simplificar y obtener la minima expresión: \( \frac{\frac{b}{a}+\frac{a-2 b}{b}}{\left(\frac{a^{2}+3 a b+3 b^{2}}{b}+\frac{b^{2}}{a}\right) \cdot(a-b)^{2}} \)

If the system \( \left\{\begin{aligned}-4 x-5 y-4 z=-3 \\ -5 x+7 y-8 z=-7 \\ -6 x+19 y+h z=k\end{aligned}\right. \) has infinitely many solutions, then \( k=\square \) and \( h= \)

For the following system to be consistent, \( \left\{\begin{array}{l}6 x_{1}-3 x_{2}-2 x_{3}=-6 \\ 5 x_{1}-8 x_{2}+k x_{3}=-4 \\ -7 x_{1}+4 x_{2}+7 x_{3}=8\end{array}\right. \) we must have \( k \neq \square \) You may enter your answer as a fraction.

5) \( (x+2)^{4}-4(x+2)^{2}-5=0 \)