
Parallel lines share the same slope, so the slope of the parallel line in this case must be
.
Point-slope form is
, where
is the slope and
is any known point on the line.
Plug in the values. 
Simplify and distribute. 
Subtract 1 from both sides. 
Since the interior is 170 the exteriro must be 10 degrees. There is a total of 360 degrees so 360/10=36 or 36 sides.
Answer:
108
Step-by-step explanation:
"At this rate, ..." means we're to assume Nancy's score is proportional to the number of holes:
score/18 = 24/4
Multiplying by 18, we get ...
score = 18(24/4) = 18(6) = 108
Nancy can expect a score of 108 on 18 holes.