7. กำหนด \( x\left[\begin{array}{c}3 \\ -1\end{array}\right]+y\left[\begin{array}{c}1 \\ -1\end{array}\right]=\left[\begin{array}{c}-1 \\ 3\end{array}\right] \) ค่า \( x \) เท่ากับข้อใดต่อไปนี้

2imalify \( \frac{x^{2}-y^{2}}{x^{2} x y} \) \( \frac{y+2 x-3 y}{3 x-2 y}=4 \), evaluate \( 2 x y \) If \( z=\sqrt{x^{2}-y^{2}} \), express \( x \) interm 9 \( y \) and 2

\( x = \frac { - ( - 1 ) \pm \sqrt { - 79 } } { 2.1 } \)

\( \left\{ \begin{array} { l } { 2 x y - y = 7 } \\ { x - 5 y - 2 } \end{array} \right. \)

2.3 Express \( \frac{1}{\sqrt{2}+1} \) in its simpl

Question 8 ( 3 marks) What is the equation of the line that passes through the points \( (1,6) \) and \( (3,2) \) ? \( y=\square x+\square \)