Question 667265
Let {{{ x }}} = pounds of sugar needed
{{{ x = .25*( x + 20 ) }}}
{{{ x = .25x + 5 }}}
{{{ .75x = 5 }}}
 x = 6 and 2/3 pounds of sugar
check:
total pounds is 26 and 2/3
{{{ ( 6 + 2/3 ) / ( 26 + 2/3 ) = .25 }}}
OK