To solve this problem, evaluate the equation for all the values of x in the options.
5:
4 is a real but a rational number, it means this option is incorrect.
0:
3i is not a real number, this option is incorrect.
-3:
0 is a real but a rational number, this option is incorrect.
4:
The square root of 7 is a real and irrational number, it means, this is the correct option.