Question 962124
{{{ f(x) = -log( 5,( 2x - 1 ) ) }}}
Multiply both sides by {{{ -1 }}}
{{{ -f(x) = log( 5,( 2x - 1 ) ) }}}
I can say {{{ y = f(x) }}}, 
and the inverse of this is:
{{{ 2x - 1 = 5^(-y) }}}
The graph doesn't exist when
{{{ 2x - 1 <= 0 }}}
{{{ 2x <= 1 }}}
{{{ x <= 1/2 }}}
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{{{ y = 0 }}}
{{{ x = 1 }}}
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{{{ y = -1 }}}
{{{ x = 3 }}}
etc.
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Here's the plot:
{{{ graph( 500, 500, -3, 6, -3, 6, -log( 5, (2x-1 ))  ) }}}