Nilai x yang Memenuhi 8³x +¹= 128x-¹

8^(3x + 1) = 128^(x -1)
2^3(3x - 1) = 2^7(x - 1)
3(3x - 1) = 7(x - 1)
9x - 3 = 7x - 7
9x - 7x = 3 - 7
2x = -4
x = -2

Nilai x yg memenuhi :
x = -2