The centroid of the triangle formed by the pair of straight lines 12x2−20xy+7y2=0 and the line 2x−3y+4=0 is
−73,73
−83,83
83,83
43,43
a=12,2h=−10,b=7,l=2,m=−3,n=4
αbl−hm=βam−hl
=−2n3(am2−2hlm+bl2)⇒(α,β)=83,83