Question

If $a,b,c$ are in $A.P.$, then the straight lines $ax+by+c=0$ wil always pass through the point ..........

• A. $(1,2)$
• B. $(1,5)$
• C. $(3,2)$
• D. None of these

Answer 1

The correct option is A $(1,2)$

$A,B,C$ in $AP$

$ax+by+c=0$ __(I)

$\therefore 2b=a+c$

$a-2b+c=0$ __(II)

comparing (I) and (II),

$x=1,y=-2$

$\therefore (1,-2)$ is the fixed point