Straight Line Question 79

Question: Given the four lines with equations $ x+2y=3, $ $ 3x+4y=7,2x+3y=4 $ and $ 4x+5y=6, $ then these lines are [IIT 1980; Pb. CET 2003]

Options:

A)Concurrent

B)Perpendicular

C)The sides of a rectangle

D)None of these

Show Answer

Answer:

Correct Answer: D

Solution:

  • These lines cannot be the sides of a rectangle as none of these are parallel nor they are perpendicular. Now check concurrency $ | \begin{matrix} 1 & 2 & -3 \\ 3 & 4 & -7 \\ 2 & 3 & -4 \\ \end{matrix} |=1(-16+21)-2(2)-3(1)\ne 0 $ Hence neither concurrent.