Question

If the lines $ax+by+c=0$ ,$bx+cy+a=0$ and $cx+ay+b=0$

$a\ne b\ne c$ are concurrent then the point of concurrency is

• A. $(0,0)$
• B. $(1,1)$
• C. $(2,2)$
• D. $(-1,-1)$

Answer 1

Answer: (B)

$(1,1)$

Given $3$ lines $ax+by+c=0;bx+cy+a=0$ and $cx+ay+b=0$ are concurrent

By inspection $a+b+c=0$ is obtained by substituting $x=y=1$

$\therefore$ point of concurrent is $(1,1)$