Step: 1
The value of c + d = 17 + 64 = 81, which is a rational number.
Step: 2
The value of c + d = 17 + 64 = 17 + 8 = 25, which is a rational number.
Step: 3
The value of 2d + c = 264 + 17 = 2(8) +17 = 16 + 17 = 33, which is a rational number.
Step: 4
The value of c + d = 17 + 64 = 64 + 17, which is an irrational number.
Correct Answer is : c + d