\( k = - 2 ; f ( x ) = 3 x ^ { 3 } - 7 x ^ { 2 } - 4 x + 18 \)

9. Use any method to solve the system: \( \left\{\begin{array}{c}x^{2}+y^{2}=9 \\ 9 x^{2}+4 y^{2}=36\end{array}\right. \)

Write the function whose graph is the graph of \( y=(x+4)^{2} \), but is reflected about the \( x \)-axis. \( y=\square \) (Simplify your answer.)

10. The perimeter of a rectangular plot of land is 72 meters and its area is \( 308 \mathrm{~m}^{2} \). What are the dimensions of the property?

\( 19 j-86 \geq 5 \) or \( 27 j-82 \leq 18 \)

Solve for \( r \). \( 3^{r}+3^{3-r}=28 \)