1
а)-π/6-π/6-π/6=-π/2
б)cos(π/6-π/3)=cos(-π/6)=cosπ/6=√3/2
2
а)sin(3x-3π/8)=6/4√3
sin(3x-3π/8)=√3/2
3x-3π/8=π/3+2πn U 3x-3π/8=2π/3+2πn
3x=17π/24+2πn U 3x=25π/24+2πn
x=17π/72+2πn/3 U x=25π/72+2πn/3,n∈z
б)cos(5x/2-1)=-2/√3<-1
решения нет
в)сtg(π/3-4x)=√3
ctg(4x-π/3)=-√3
4x-π/3=-π/6+πn
4x=π/6+πn
x=π/24+πn/4,n∈z
г)cos(3π/2-x)-5cosx=0
-sinx-5cosx=0/cosx
-tgx-1=0
tgx=-1
x=-π/4+πn,n∈z
1)4а·(-3ab)=-12a²b
2) -2m²·0,1m⁴n·(-5n³)=(-2·0,1·(-5))·m⁶n⁴=m⁶n⁴
3(x2-2x+1)-3x+15=21
3X2-6x+3-3x+15=21
3x2-9x+18=21
3x2-9x=21-18
3x2-9x=3
3x(x-3)=3 3x=3
x=1
x-3=3
x=6