If the equation $3x^{2}+10xy+3y^{2}+16y+k=0$ represents a pair of lines,then the value of $k$ is

The separate equations of the lines represented by $4x^{2}-y^{2}+2x+y=0$ are

If $\alpha x^2+2 \gamma x y+\beta y^2=0$ is the equation of a pair of lines passing through the origin and perpendicular to the pair of lines $b h x^2+a b x y+a h y^2=0$ $(a \neq 0, b \neq 0)$,then $\frac{\alpha \beta}{\gamma^2}=$

The lines represented by the equation $x^2-y^2-x+3y-2=0$ are :

If $ax^2-xy-3y^2-5x+20y+c=0$ represents a pair of lines passing through the point $(2,3)$,then $a-c=$

The image of the pair of lines represented by $ax^2 + 2hxy + by^2 = 0$ by the line mirror $y = 0$ is