4sin6xcosx-2sin5x=1
4sin6xcosx-2sin(6x-x)=1
4sin6xcosx-2(sin6xcosx-sinxcos6x)=1
4sin6xcosx-2sin6xcosx+2sinxcos6x=1
2sin6xcosx+2sinxcos6x=1
2sin(6x+x)=1|:2
sin7x=1/2
7x=π/6+2kπ |7 ∨ 7x=(π-π/6)+2kπ |:7 , k∈C
x=π/42+2/7kπ ∨ x=5/42π+2/7kπ