Question 857122
{{{ log( 9, 3u + 14 ) - log( 9, 5 ) = log( 9, 2u ) }}}
The minus sign means you divide
This is the general rule:
{{{ log(a) - log(b) = log( a/b ) }}}
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{{{ log( 9, ( 3u + 14 ) / 5 ) = log( 9, 2u ) }}}
{{{ ( 3u + 14 ) / 5 = 2u }}}
{{{ 3u + 14 = 10u }}}
{{{ 7u = 14 }}}
{{{ u = 2 }}}
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check:
{{{ log( 9, 3u + 14 ) - log( 9, 5 ) = log( 9, 2u ) }}}
{{{ log( 9, 3*2 + 14 ) - log( 9, 5 ) = log( 9, 2*2 ) }}} 
{{{ log( 9, 20 ) - log( 9, 5 ) = log( 9, 4 ) }}}
{{{ log( 9, 20/5 ) = log( 9, 4 ) }}}
{{{ log( 9, 4 ) = log( 9, 4 ) }}}
OK