Straight Line Question 384

Question: If a and b are two arbitrary constants, then the straight line $ (a-2b)x+(a+3b)y+3a+4b=0 $ will pass through [RPET 1990]

Options:

A) $ (-1,\ -2) $

B)(1, 2)

C) $ (-2,\ -3) $

D)(2, 3)

Show Answer

Answer:

Correct Answer: A

Solution:

  • $ (a-2b)x+(a+3b)y+3a+4b=0 $ or $ a(x+y+3)+b(-2x+3y+4)=0 $ , which represents a family of straight lines through point of intersection of $ x+y+3=0 $ and $ -2x+3y+4=0 $ i.e, (? 1, ? 2). Trick: Point (-1, -2) satisfies the given equation of straight line.