SOLUTION: Members of the student council are conducting a fundraiser by selling school calendars. After selling 80 calendars, they had a loss of $360. After selling 200 calendars, they had a

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Members of the student council are conducting a fundraiser by selling school calendars. After selling 80 calendars, they had a loss of $360. After selling 200 calendars, they had a      Log On


   

Question 1127446: Members of the student council are conducting a fundraiser by selling school calendars. After selling 80 calendars, they had a loss of $360. After selling 200 calendars, they had a profit of $600. Write an equation that describes the relation between y, the profit or loss, and x, the number of calendars sold. How much profit did they make from selling each calendar? How much would they have lost if they had sold no calendars?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You are given 2 points:
( 80, -360 )
( 200, 600 )
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Use general point-slope formula
+%28+y+-%28-360%29+%29+%2F+%28+x+-+80+%29+=+%28+600+-%28-360%29+%29+%2F+%28+200+-+80+%29+
+%28+y+%2B+360+%29+%2F+%28+x+-+80+%29+=+960+%2F+120+
+y+%2B+360+=+8%2A%28+x+-+80+%29+
+y+%2B+360+=+8x+-+640+
+y+=+8x+-+1000+
--------------------------
+600%2F200+=+3+
They made $3 profit/calendar
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If +x=0+, ( no calendars sold ),
they lose $1000 since
+y+=+8%2A0+-+1000+
+y+=+1000+