SOLUTION: Suppose the number of pages an author produces is related to the time she spends writing by a linear equation. To produce 9 pages requires 120 minutes of writing and to produce 17

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Question 945556: Suppose the number of pages an author produces is related to the time she spends writing by a linear equation. To produce 9 pages requires 120 minutes of writing and to produce 17 pages requires 200 minutes. If she writes for 360 minutes how many pages will she produce?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Plot pages on the vertical axis
Plot minutes on the horizontal axis
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You are given 2 points:
( 120, 9 )
( 200, 17 )
Let +p+ = number of pages
Let +t+ = number of minutes
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Use the general point-slope formula
+%28+p+-+9+%29+%2F+%28+t+-+120+%29+=+%28+17+-+9+%29+%2F+%28+200+-+120+%29+
++%28+p+-+9+%29+%2F+%28+t+-+120+%29+=+8+%2F+80+
++%28+p+-+9+%29+%2F+%28+t+-+120+%29+=+1%2F10+
+p+-+9+=+%28+1%2F10+%29%2A%28+t+-+120+%29+
+10p+-+90+=+t+-+120+
+10p+=+t+-+30+
+p+=+%28+1%2F10+%29%2At+-+3+
----------------------
check:
does it go through ( 120,9 ) ?
+9+=+%28+1%2F10+%29%2A120+-+3+
+12+=+12+
OK
does it go through ( 200,17 ) ?
+17+=+%28+1%2F10+%29%2A200+-+3+
+20+=+20+
OK
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given:
+t+=+360+
+p+=+%28+1%2F10+%29%2At+-+3+
+p+=+%28+1%2F10+%29%2A360+-+3+
+p+=+36+-+3+
+p+=+33+
She will write 33 pages