Questions in pair-st-lines

Select	Question
	If the equation $12{{x}^{2}}-10xy+2{{y}^{2}}+11x-5y+k=0$ represents two straight lines, then the value of k is
	If two sides of a triangle are represented by ${{x}^{2}}-7xy+6{{y}^{2}}=0$ and the centroid is (1, 0) then the equation of third side is
	The equation $4{{x}^{2}}-24xy+11{{y}^{2}}=0$represents
	If the slope of one of the lines given by $a{{x}^{2}}+2hxy+b{{y}^{2}}=0$is 5 times the other, then
	The equation to the pair of straight lines through the origin which are perpendicular to the lines $2{{x}^{2}}-5xy+{{y}^{2}}=0,$is
	The area of the triangle formed by the lines ${{x}^{2}}-4{{y}^{2}}=0$and $x=a$, is
	If the lines represented by the equation $6{{x}^{2}}+41xy-7{{y}^{2}}=0$ make angles $\alpha $and $\beta $ with x-axis, then $\tan \alpha .\tan \beta $=
	Difference of slopes of the lines represented by equation ${{x}^{2}}({{\sec }^{2}}\theta -{{\sin }^{2}}\theta )-2xy\tan \theta +{{y}^{2}}{{\sin }^{2}}\theta =0$is
	The value of $\lambda ,$ for which the equation ${{x}^{2}}-{{y}^{2}}-x$–$\lambda y-2=0$represent a pair of straight line, are
	If $a{{x}^{2}}-{{y}^{2}}+4x-y=0$represents a pair of lines then $a=$