4.61
2^x/4+8/2^x=3
2^x=a
a/4+8/a-3=0
a²-12a+32=0
a1=a2=12 U a1*a2=32
a1=4⇒2^x=4⇒x=2
a2=8⇒2^x=8⇒x=3
4.63
5^x-5^x/4=4
5^x=a
a-5/a-4=0
a²-4a-5=0
a1+a2=4 U a1*a2=-5
a1=-1⇒5^x=-1 нет решения
a2=5⇒5^x=5⇒x=1
4.65
1/9*(1/9)^x-(1/3)^x=0
(1/3)^x *(1/9*(1/3)^x -1)=0
(1/3)^x=0 нет решения
1/9*(1/3)^x=1⇒(1/3)^x=9⇒x=-2
4.80
(2*5)^(x²-1)=10^-3*10^(3x+6)
10^(x²-1)=10^(3x+3)
x²-1=3x+3
x²-3x-4=0
x1+x2=3 U x18x2=-4
x1=-1 U x2=4