Question

The straight lines `x+2y-9=0,3x+5y-5=0` , and `a x+b y-1=0` are concurrent, if the straight line `35 x-22 y+1=0` passes through the point `(a , b)` (b) `(b ,a)` `(-a ,-b)` (d) none of these
A. (a,b)
B. (b,a)
C. (-a,-b)
D. none of these

Answer 1

Correct Answer - A
The three lines are concurrent if
`|{:(1,2,-9),(3,5,-5),(a,b,-1):}|=0`
or 35a-22b+1 = 0
which is true is the line 35x-22y+1=0 passes through (a,b).