Question 946853
You can think of this as one car moving 
at the sum of their speeds and the other
car standing still
Let {{{ s }}} = the speed of the slower car in mi/hr
{{{ s + 8 }}} = the speed of the faster car in mi/hr
------------------
{{{ 704 = ( s + s + 8 )*8 }}}
{{{ 704 = ( 2s + 8 )*8 }}}
{{{ 704 = 16s + 64 }}}
{{{ 640 = 16s }}}
{{{ s = 40 }}}
{{{ s + 8 = 48 }}}
------------------
The speed of the slower car is 40 mi/hr
The speed of the faster car is 48 mi/hr
check:
{{{ d[1] = 40*8 }}}
{{{ d[1] = 320 }}}
and
{{{ d[2] = 48*8 }}}
{{{ d[2] = 384 }}}
and
{{{ d[1] + d[2] = 320 + 384 }}}
{{{ d[1] + d[2] = 704 }}}
OK