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| Question 2465:  Can you help me with this word problem that I am struggling with?
 The distance D between a fixed spring and the floor is a linear function of the weight w attached to the bottom of the spring. The spring is 12 inches from the floor when the weight is 2 grams, and the spring is 7 inches from the floor when the weight is 4 grams. Write D as a linear function of w.
 Answer by khwang(438)
      (Show Source): 
You can put this solution on YOUR website!  Let D = aW +b, when W = 2, D = 12, so 12 = 2a + b...(1)
 when W = 4, D = 7, so 7 = 4a + b...(2)
 (2)-(1): 2a = -5, or a = -2.5,
 hence b = 12+ 2*2.5 = 17.
 Answer: D = -2.5W + 17.
 Kenny
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