Pair Of Straight Lines Question 152

Question: The equation $ {{(x-5)}^{2}}+(x-5)(y-6)-2{{(y-6)}^{2}}=0 $ represents

Options:

A) A circle

B) Two straight lines passing through origin

C) Two straight lines passing through the point (5, 6)

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

$ {{(x-5)}^{2}}+(x-5)(y-6)-2{{(y-6)}^{2}}=0 $

Therefore $ x^{2}+25-10x+xy+30-6x-5y-2y^{2}-72+24y=0 $

$ \Rightarrow x^{2}+xy-2y^{2}-16x+19y-17=0 $

Obviously, it is not a circle as $ a\ne b $ and xy is present.

On checking for pair of straight lines, we get that the equation represents a pair of straight lines.

Also for $ x=5,\ y=6, $ equation vanishes. Therefore it passes through (5, 6).