Question 111488
first one, {{{11 - 5log3 (x - 5) = 6}}}
{{{ 5log_3 (x - 5) = 5 }}}
{{{ log_3 (x-5) = 1 }}}
At this point you can take both sides to be exponents of 3
{{{ 3^(log_3 (x - 5)) = 3^6}}}
{{{x-5=3^6}}}
{{{x=3^6+5}}}
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second one {{{log x = 1 - log(x + 3)}}}

take both sides to be an exponent of 10

{{{10^(log x) = 10^(1 - log(x + 3))}}}
{{{ x = 10/(x+3) }}}
{{{x^2 + x - 10=0}}}

Just check for extranous values, because there is only one solution  to the problem but the quadratic will give you two.
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third one. Here, it would have been helpful if you had been more clear. is it {{{(e^6)^y}}} or {{{e^(6^y)}}}. This is not communitive, meaning these mean different things. I'm going to assume you meant the second one because that is the literal translation of what you said. 
{{{e^6^y = 25}}}
Take natural log of both sides
{{{ 6^y = ln(25) }}}
Take log base 6 of both sides 
{{{ y = log_6(ln(25))}}}