1) 2cos(п/3-3x)-корень3=0 2) 3+4sin(2x+1)=0 3)1-tg(x+п/7)=0

1) Cos (π/3 - 3x ) = √3/2
    π/3 - 3x = +- arcCos √3/2 +2πk , k∈Z
   - 3 x = +-π/6 + 2πk - π/3 , k∈Z
     x = +- π/6 - 2π/9 + π/9, k ∈Z
2)4Sin(2x + 1) = -3
  Sin (2x + 1) = - 3/4
   2 x + 1 = (-1)^n arcSin(-3/4) + nπ, n ∈Z
   2x = (-1)^(n+1)arcSin 3/4 + nπ -1 , n∈Z
    x = (-1)^(n + 1)(arcSin 3/4)/2 + πn/2 + 1/2, n ∈Z 
3) tg( x +π/7) = 1
   x + π/7 = arctg 1 + πk , k∈Z
   x = π/4 + πk - π/7 , k ∈Z
    x = 3π/28 + πk , k∈Z