Q.

In ΔABC, the equation of altitudes AM and BN are x+5y-3=0, x+y-k=0. If the altitude CL is given by 3x-y-1=0, then k= ______.


Ans.

(1)

Solving the altitudes AM and CL, we get

Orthocentre=(12,12)  lies on x+y-k=0⇒k=1