42. \( \frac{3 x+y}{2 x+3+z} \quad \operatorname{per} x=-\frac{1}{9} \quad y=\frac{1}{2} \quad, \quad z=\frac{2}{9} \)

Use the elimination method to find all solutions of the system: \( \left\{\begin{array}{l}x^{2}-2 y=7 \\ x^{2}+5 y=14\end{array}\right. \) The two solutions of the system are: (the one with \( x<0 \) is) \( x=\square \) \( y=\square \) (the one with \( x>0 \) is) \( x=\square \) \( y=\square \)

4. \( x^{2}-6 x+8 \leq 0 \)

Solve the system if possible by using Cramer's rule. If Cramer's rule does not apply, solve the system by using another meth Write all numbers as integers or simplified fractions. \[ \begin{array}{l}7 x+7 y=-19 \\ \\ -9 x-5 y=4 \\ \text { Part: } 0 / 2 \\ \text { Part } 1 \text { of } 2 \\ \text { Evaluate the determinants } D_{1} D_{x} \text {, and } D_{y} \\ D=\square\end{array} \] \( \square \)

14. Uttrycken nedan har samma positiva värde på \( a \). Vilka tal ska stå i rutorna så att likheterna stämmer? \( a^{\frac{1}{3}}=\square \quad a^{\frac{2}{3}}=9 \)

\( \frac { 3 ) } { 3 x + 4 } = \frac { 2 x - 8 } { 3 } \)