Ayuda con ejercicios de logaritmo

Continuamos:
b)
S=log(1/3)9+log0,1+log(2)0,25
S = log(1/3)([1/(1/3)]^2) + log(1/10) + log(2) ([1/2]^2) =
(-1)·2 -1 +(-1)·2 = -2 -1 -2 = -5
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c)
S=log(1/5)1/25-log(1/49)7+log(1/10)0,01-log(0,5)1/2
S = log(1/5)[(1/5)^2] - log(1/49)sqrt[1/(1/49)]+ log(1/10) (1/10)^2 - log(0,5)0,5
S= 2 - (1/2)(-1) + 2 - 1 = 2 + 1/2 + 2 -1 = 7/2 = 3,5
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d)
log(b)x=log(b)7+log(b)5
log(b)x=log(b)7·5
log(b)x = log(b)35
x = 35
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e)
log(b)x=2log(b)11
log(b)x=log(b)11^2
log(b)x=log(b)121
x = 121
----------------------
f)
log(b)x=2log(b)6-log(b)18
log(b)x=log(b)(6^2)-log(b)18
og(b)x=log(b)36/18
log(b)x= log(b)2
x= 2
------------------------
log(b)x=1/2log(b)81-2log(b)3
log(b)x=log(b)sqrt(81)-log(b)3^2
log(b)x=log(b)9/9
log(b)x=log(b)1
x = 1
Y eso es todo, espero que te sirva y lo hallas entendido. No olvides puntuar o pedir aclaraciones.