8cos(2x-1)-4=0
cos(2x-1) = 4/8
cos(2x-1) = 1/2
2x-1 = +-п/3 + 2пn, n∈ Z
2x = +-п/3 + 1 + 2пn, n∈ Z
x = +-п/6+ 1/2 + пn, n∈ Z
ответ: +-п/6+ 1/2 + пn, n∈ Z
