document.write( "Question 1141800: (a) The volume of a box is represented by the function, V(x)=x^3+5x^2+2x-8.
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document.write( "If the height of the box is represented by (x+4), determine the possible dimensions(binomials) of the box. Is there any restriction on the value of x?
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document.write( "(b) If the volume of the box is 70cm^3 determine possible whole number value(s) for x. \n" );
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Algebra.Com's Answer #762444 by greenestamps(13215) You can put this solution on YOUR website! \n" ); document.write( "(a) The volume of the box is length times width times height; you are given that the height is x+4. \n" ); document.write( "(1) Use synthetic division to remove the factor (x+4). \r\n" ); document.write( "\r\n" ); document.write( " -4 | 1 5 2 -8\r\n" ); document.write( " | -4 -4 8\r\n" ); document.write( " +-----------------\r\n" ); document.write( " 1 1 -2 0 \n" ); document.write( "So \n" ); document.write( " \n" ); document.write( "(2) Factor the quadratic. \n" ); document.write( " \n" ); document.write( "ANSWER: The possible dimensions of the box are (x-1), (x+2), and (x+4). Since dimensions of a box must be positive, the restriction is that x has to be greater than 1. \n" ); document.write( "(b) You could use any number of methods to solve the equation \n" ); document.write( " \n" ); document.write( "However, since we know x > 1 and we are looking for whole number values for x, we can quickly find the solution by logical trial and error. \n" ); document.write( "x=2: (x-1)(x+2)(x+4) = (1)(4)(6) = 24 no... \n" ); document.write( "x=3: (x-1)(x+2)(x+4) = (2)(5)(7) = 70 YES! \n" ); document.write( "And clearly larger values of x will produce volumes greater than 70. \n" ); document.write( "ANSWER: x=3 makes the volume 70 \n" ); document.write( " |