The condition for three lines a1x+b1y+c1=0, a2x+b2y+c2=0 and a3x+b3y+c3=0 , to be concurrent is
∣∣
∣∣a1b1c1a2b2c2a3b3c3∣∣
∣∣=0
True
This is a result from determinants.
a1x+b1y+c1=0
a2x+b2y+c2=0 and
a3x+b3y+c3=0 are concurrent if
∣∣ ∣∣a1b1c1a2b2c2a3b3c3∣∣ ∣∣=0