Решение
1) 2 cos60° + cos30° = 2*(1/2) + √3*(√3/2) = 1 + 3/2 = 2,5
2)5 sin30°-ctg45° = 5*(1/2)*1 = 5/2 = 2,5
3)2 sin30° + 6 cos60°-4 tg45° = 2*(1/2) + 6*(1/2) - 4* 1 = 1 + 3 - 4 = 0
4)3 tg45° * tg60° = 1 * (√3) = √3
5)4 tg60° * sin60° = √3*(√3/2) = 3/2 = 1,5
6)12 sin60° * cos60° = 12*(√3/2)*(1/2) = 3√3