Question 665512
{{{ 5*( n+7 )/7=7 }}}
Multiply both sides by {{{ 7 }}}
{{{ 5*( n + 7 ) = 49 }}}
{{{ 5n + 35 = 49 }}}
Subtract {{{ 35 }}} from both sides
{{{ 5n = 14 }}}
Divide both sides by {{{ 5 }}}
{{{ n = 14/5 }}} 
check answer:
{{{ 5*( 14/5 + 7 )/7=7 }}}
Note that {{{ 7 = 35/5 }}}
{{{ 5*( 14/5 + 35/5 )/7=7 }}}
{{{ 5*( 49/5 )/7=7 }}}
Multiply both sides by {{{ 7 }}}
{{{ 5*(49/5) = 49 }}}
Divide both sides by {{{ 5 }}}
{{{ 49/5 = 49/5 }}}
OK