If the slope of one line of the pair of lines represented by ax2+10xy+y2=0 is four times the slope of the other, then a is equal to

If m1,m2 are the slopes of two lines whose combined equation is ax2+2hxy+by2=0 then the relation between the slopes and the coefficients of equation are  m1+m2=−2hb,m1m2=abSince the slopes of the lines represented by the equation ax2+10xy+y2=0 are one is four times of the other. Hence,m+4m=10⇒m=−2 and m⋅4m=a⇒a=16Therefore, a=16