В)-5х=6
х=-6/5
х=-1 1/5
х=-1.2
г) 8х+8х=4.61-0.77
16х=3.84
х=0.24
х=6/25
ОДЗ x≠7 U x≠-9
log(4)(7-x)²+log(4)(x+9)²-log(4)(x+9)²=4
log(4)(7-x)²=4
(7-x)²=4^4
|7-x|=16
7-x=-16 U 7-x=16
x=7+16 U x=7-16
x=23 U x=-9∉ОДЗ
Решение
Cos2x=1+sinx
1 - 2sin²x - sinx = 1
sinx(2sinx + 1) = 0
1) sinx = 0
x₁ = πk, k∈Z
2) 2sinx + 1 = 0
sinx = - 1/2
x = (-1)^n *arcsin(- 1/2) + πn, n∈Z
x = (-1)^(n + 1) *arcsin(1/2) + πn, n∈Z
x₂ = (-1)^(n + 1) *(π/6) + πn, n∈Z
<span>Ответ: x₁ = πk, k∈Z ; x₂ = (-1)^(n + 1) *(π/6) + πn, n∈Z</span>