The equation of the line passing through the point of intersection of the straight lines `x/a+y/b=1, x/b+y/a=1` and having slope zero is

Options

A. bx-ay=0
B. x+y=0
C. ax-by=0
D. x-y=0

Answer

D

Explanation

Point the intersection of ` x/a + y/b =1 and x/b + y/a =1` is
` ((ab)/(a+b) + (ab)/(a+b))`
Now the equation of line joining (0,00 and ` ((ab)/(a+b) , (ab)/(a+b))`
Now, the equation of line joining (0,0) and ` ((ab)/(a+b) , (ab)/(a+b))`
is x=y i.e, x-y=0