11 Semplifica la seguente espressione: \[ \left(\frac{1}{y^{2}+y}-\frac{1}{y^{2}-y-2}-\frac{1}{y^{2}+2 y+1}\right) \cdot \frac{y^{3}+2 y^{2}+y}{2+y^{2}} \]

\begin{tabular}{l} Exercice 5 \\ Exercice 6 \\ exminer les entiers naturels xpour que le nombre 31x8 soit divisible 3 et 4 \\ \hline\end{tabular}

Solve simultaneously for \( x \) and \( y \) \( \begin{array}{l}3 x-y=2 \quad \text { and } \quad 2 y+9 x^{2}=-1 \\ \text { Discuss the nature of the roots of } 2 x^{2}-4 x+2=0\end{array} \)

determine the evadrant in which the angles lies \( \begin{array}{ll}\text { a) } \frac{40 s^{\circ}}{} & \text { b) } \frac{\pi}{7}\end{array} \)

\( ( A \cap B ) ^ { \prime } \cap ( A \cup B ) = ( A \cup B ) - ( A \cap B ) \)

Simplify using factors: \( \frac{2 a-2 b}{-a+b} \)