Question 732757

The problem only talks about dozens of
flowers, so that is the unit to use
Let {{{ x }}} = dozens of roses she bought
{{{ 17 - x }}} = dozens of carnations she bought
given:
{{{ 15x + 8*( 17 - x ) = 192 }}}
{{{ 15x + 136 - 8x = 192 }}}
{{{ 7x = 56 }}}
{{{ x = 8 }}}
She bought 8 dozen roses
check:
{{{ 15*8 + 8*( 17 - 8 ) = 192 }}}
{{{ 120 + 8*9 = 192 }}}
{{{ 120 + 72 = 192 }}}
{{{ 192 = 192 }}}
OK