1) Cos5π/3 = Cos(2π - π/3) = Cosπ/3 = 1/2
2) tg(- 5π/6) = - tg(π - π/6) = tgπ/6 = 1/√3 = √3/3
3) tgπ*ctgπ/4 + Cosπ/2*Sin(-2π/3) = 0*1- 0*Sin2π/3 = 0
4) Sin150° - Cos720° + tg225° = Sin(180 - 30) - Cos(2*360 +0) + tg(270 - 45) =
= Sin30° - Cos0 + ctg45°= 1/2 - 1 + 1 = 1/2 = 0,5
На фото...........................
1)4c(4c-1)-3(4c-1)²=16c²-4c-3(16c²-8c+1)=16c²-4c-48c²+24c-3=20c-32c²-3
2)8m(m-3)-3(m-3)²=8m²-24-3(m²-6m+9)=8m²-24-3m²+18m-27=5m²-51+18m
=(3-3+2)/(√5-√3-√5-√3)=2/(-2√3)=-1/√3=-√3/3