SOLUTION: when the price,p, charged for a boat tour was $25, the average number of passengers per week, N, was 500. when the price was reduced to $20, the average number of passengers per we

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: when the price,p, charged for a boat tour was $25, the average number of passengers per week, N, was 500. when the price was reduced to $20, the average number of passengers per we      Log On


   



Question 1010614: when the price,p, charged for a boat tour was $25, the average number of passengers per week, N, was 500. when the price was reduced to $20, the average number of passengers per week increased to 650.
find a formula for the demand by finding N as a function of the price,p.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Find +N+ as a function of price +p+
You are given 2 points, ( p, N )
( 25, 500 )
( 20, 650 )
Use general point-slope formula
+%28+N+-+500+%29+%2F+%28+p+-+25+%29+=+%28+650+-+500+%29+%2F+%28+20+-+25+%29+
+%28+N+-+500+%29+%2F+%28+p+-+25+%29+=+150+%2F+%28-5%29+
+%28+N+-+500+%29+%2F+%28+p+-+25+%29+=+-30+
+N+-+500+=+-30%2A%28+p+-+25+%29+
+N+=+-30p+%2B+750+%2B+500+
+N+=+-30p+%2B+1250+
----------------------------
check:
( 25,500 )
+N+=+-30p+%2B+1250+
+500+=+-30%2A25+%2B+1250+
+500+=+-750+%2B+1250+
+500+=+500+
and
( 20, 650 )
+N+=+-30p+%2B+1250+
+650+=+-30%2A20+%2B+1250+
+650+=+-600+%2B+1250+
+650+=+650+
OK