Question 285566
If they are driving directly opposite eachother,
you can just add their speeds
Let {{{s}}}mi/hr = speed of slower car
Then {{{s + 10}}} mi/hr = speed of faster car
{{{1040 = (s + s + 10)*8}}} mi
{{{1040 = (2s+ 10)*8}}} 
{{{1040 = 16s + 80}}}
{{{1040 - 80 = 16s}}}
{{{16s = 960}}}
{{{s = 60}}}
The speed of the slower car is 60 mi/hr
check:
{{{1040 = (2s+ 10)*8}}} 
{{{1040 = (2*60+ 10)*8}}}
{{{1040 = 130*8}}}
{{{1040 = 1040}}}
OK