Write an equation in the form \( y=m x+b \) of the line that is described. The \( y \)-intercept is -9 and the line is parallel to the line whose equation is \( 5 x+y=6 \).

a) \( \left(-2 x^{2}\right)\left(x^{2}-2 x+3\right) \frac{1}{2} \)

24 Expresa com a identitats notables. \( \begin{array}{ll}\text { a) } 49 x^{2}-16 & \text { b) } 36 x^{2}-1 \\ \text { c) } x^{2}-18 x+81 & \text { d) } 121-100 x^{2} \\ \text { e) } 9 x^{2}+12 x+4 & \text { f) } 9 x^{2}-24 x+16 \\ \text { g) } 25-100 y^{2} & \text { h) } 4 x^{2}+16 x+16\end{array} \)

Qual è il grado di un polinomio se la funzione \( f(x) = 2x^4 - 3x^3 + x - 5 \)?

17. \( 5 x^{2}+12 x-2=0 \)

\( -\frac{1}{2 x}-\frac{1}{y}=-1 \) and \( \frac{1}{x}+\frac{1}{2 y}=8 \)