6x+1-12-8x=4
2x-11=4
2x=4+11
2x=15
x=7,5
376=2*2*2*47
2640=2*2*5*67
1) 4sinx > 2
sinx > 1/2
arcsin(1/2) + 2πn < x < π - arcsin(1/2) + 2πn, n∈Z
π/6 + 2πn < x < π - π/6 + 2πn, n∈Z
π/6 + 2πn < x < 5π/6 + 2πn, n∈Z
2) 2tg 2x+ 8> 0
tg2x > - 4
- arctg4 + πk < 2x < π/2 + πk, k∈Z
-(1/2)*arctg4 + (πk)/2 < x < π/4 + (πk)/2, k∈Z,
3) 5cos 2 x+2<7
5 cos2x < 5
cosx < 1
arccos(1) + 2πm < 2x < 2π - arccos(1) + 2πm, m∈Z
0 + 2πm < 2x < 2π - 0 + 2πm, m∈Z
2πm < 2x < 2π + 2πm, m∈Z
πm < x <π + πm, m∈Z
1)4х-2=0,4х=2,х=2/4,х=1/2
2)-5х+3=0,-5х=-3,х=3/5
3)8х-4=0,8х=4,х=4/8,х=1/2 и так далее