Let ABC be a triangle. Let A be the point (1, 2) y = x is the perpendicular bisector of AB and x – 2y + 1 = 0 is the angle bisector of C. If equation of BC is given by ax + by – 5 = 0, then value of (a + b) is (1) 1 (2) 2 (3) 3 (4) 4

are you sure about the options . the answer is coming out to be 5

yes. the question is absolutely correct. the answer was coming out to be 1 thru vectors,but i m not sure if my solution is correct

Slope of AB= -1.

Find eqn of AB using slope one point form. Solve with y=x.

Using section formula find B.

Take image of A wrt to