Firstly we find the cartesian equation of the given plane.
→r.(2^i+^j−^k)−5=0
(x^i+y^j+z^k).(2^i+^j−^k)=0
⇒2x+y−z=5 is the required cartesian equation.
⇒2x5+y5−z5=1
⇒x5/2+y5+z−5=1
Comparing this with xa+yb+zc=1, we have a=52,b=5 and c=−5
Thus, the given plane cuts off intercepts 52,5,−5 along the three axes.
Hence, required sum of intercepts is
= 52+5−5
= 52