a) 2Сtgx+5=3tgx | * tgx
2 + 5tgx = 3tg²x
tgx = t
3t² - 5t -2 = 0
D = 49
t₁ = 2 t₂=-1/3
tgx = 2 tgx = -1/3
x = arctg2 + πk, k ∈Z x = -arvtg(1/3) + πn , n ∈Z
b) 3tg^2x-√3tgx=0
tgx(3tgx -√3) = 0
tgx = 0 или 3tgx -√3 = 0
x = nπ, n ∈Z 3tgx = √3
tgx = √3/3
x = π/6 + πk , k ∈Z