Part A:
If (7^2)^x = 1 then the value of x is equal 0
Because when x = 0 the
(7^2)^0 = 1 ; 7^0 = 1
Any number with 0 exponent is always equal 0, except 0.
Part B:
If (7^0)^x = 1, then the value of x is all real number
Because when 0 multiplies any number, it is always equal 0. So then 7^0 is always equal 1.
Example
if x = 1 then (7^0)^1 = 7^0 = 1
if x = -1 then (7^0)^(-1) = 7^0 = 1
if x = 1000 then (7^0)^(1000) = 7^0 = 1