Question 540529
Note that {{{ root(3,-125) = -5 }}}
and
 {{{ 189 = 7*27 }}} 
{{{ 189 = 7*3^3 }}}
so
{{{ root(3,189) = 3*root(3,7) }}}
also,
{{{ 56 = 7*8 }}}
{{{ 56 = 7*2^3 }}}
{{{ root(3,56) = 2*root(3,7) }}}
Now the problem becomes
{{{ (3/5)*(-5) - (1/4)*2*root(3,7) + (1/2)*3*root(3,7) }}}
{{{ -3 - (1/2)*root(3,7) + (3/2)*root(3,7) }}}
{{{ -3 + ( root(3,7)/2 )*( 3 - 1 ) }}}
{{{ -3 + root(3,7) }}}