4)loq(3)x=loq(3)1-loq(3)243
loq(3)x=loq(3)1/243
x=1/243=3^(-5)
6)loq(3)(x=1)=4
loq(3)(x+1)=loq(3)(3^4)
x+1=81
x=80
ОДЗ x+1>0
x> -1
7)loq(1/2)(x+23)<=2<br>loq(1/2)(x+23)<=loq(1/2)(1/2^2)<br>x+23>=1/4
x>= -22.75
ОДЗ
x+23>0
x> -23
x∈[-22.75;+∞)
8) (loq(3)x)^2-2loq(3)x=3
loq(3)x=y
y^2-2e-3=0
D=4+12=16
y1=(2+40/2=3
y2=(2-4)/2= -1
loq(3)x=3
x=27
loq(3)x= -1
x= 1/3
ОДЗ x>0
9)x+y=7 ОДЗ x>0 y>0
lqx+lqy=1
x=7-y
lq(7-y)+lqy=1
x=7-y
lq((7-y)*y)=lq10
7y-y^2-10=0
D=49-40=9
y1=(-7+3)/-2= 2
y2=(-7-3)/-2=5
x1=7-2=5
x2=7-2=5
ответ х1=5 у1=2 х2=2 у2=5