a) 25 . 5x+2 = 625
=> 5x+2 = 625 : 25
=> 5x+2 = 25
=> 5x+2 = 52
=> x + 2 = 2
=> x = 0
b) 9x-5 . 9x = 729
=> 9x-5+x = 93
=> x-5+x = 3
=> 2x - 5 = 3
=> 2x = 8
=> x = 4
c) (3x - 2)4 = 0
=> (3x - 2)4 = 04
=> 3x - 2 = 0
=> 3x = 2
=> x = \(\frac{2}{3}\)
d) 2x+6 . 2 = 128
=> 2x+6 = 64
=> 2x+6 = 26
=> x + 6 = 6
=> x = 0