Question 201166
Vol = 50x^3 -2x +75x^2 -3
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looking  for  V = L * W * H
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factor  original  eqn
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2x(25x^2 -1) +3(25x^2-1)
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(2x+3)( 25x^2 -1)
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(2x+3) (5x+1)(5x-1),,,,,sides  of  box
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2x+3 =0,,,,,x=-1.5
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5x +1 = 0,,,,,x= -1/5
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5x-1=0,,,,,,x= 1/5
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Smallest  zero  is  (-1.5),,  therefore  x> -1.5