Question 1050682
The distance he drives through towns is:
{{{ 50c }}} km
The distance he drives on the highway is:
{{{ 90*( 6 - c ) }}}
-------------------
{{{ d(c) = 50c + 90*( 6 - c ) }}}
{{{ d(c) = 50c + 540 - 90c }}}
{{{ d(c) = -40c + 540 }}} km
--------------------------
The domain begins at {{{ c = 0 }}}
and ends at {{{ d(c) = 0 }}}
{{{ 0 = -40c + 540 }}}
{{{ 40c = 540 }}}
{{{ c = 13.5 }}}
0 < c < 13.5
--------------------
The range is
0 < d(c) < 540
--------------------
Here's the plot:
{{{ graph( 400, 400, -5, 40, -70, 700, -40x + 540 ) }}}