1) 2cosx + 1 < 0
cosx <-1/2
cosx=-1/2
x1=120
x2=240
120<x<240
2) 2sinx≤√2
sinx≤√2/2
sinx=√2/2
x1=45
x2=135
45≥x≥135
1) 1376: (34 - х) =86 2)) 9680 : (х+219) = 16
1376 : 86 = 16 9680 : 16 = 605
34 - х = 16 х + 219 = 605
х =34-16 х = 605 - 219
х = 18 х = 386
3)) (х - 57) : 29 = 205
х-57= 205 * 29
х-57= 5945
х = 5945 + 57
х = 6002
4)) (х-72)*9=927
х-72 = 927: 9
х- 72 = 103
х = 103+72
х = 175
1) 2 cos x +1<0
2cosx<1
cos x<1/2
x<+- pi/6 + 2pi n