document.write( "Question 188850This question is from textbook
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document.write( ": A rectangular piece of cardboard is 2 units longer than it is wide. From each of its corners a square piece 2 units on a side is cut out. The flaps are then turned up to form an open box that has a volume of 70 cubic units. Find the length and width of the original piece of cardboard.\r
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Algebra.Com's Answer #141619 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! A rectangular piece of cardboard is 2 units longer than it is wide. \n" ); document.write( " From each of its corners a square piece 2 units on a side is cut out. \n" ); document.write( " The flaps are then turned up to form an open box that has a volume of 70 cubic units. \n" ); document.write( " Find the length and width of the original piece of cardboard. \n" ); document.write( ": \n" ); document.write( "Let x = the width of the cardboard \n" ); document.write( "then \n" ); document.write( "(x+2) = the length of the cardboard \n" ); document.write( ": \n" ); document.write( "4 units will be subtracted from the length and width \n" ); document.write( ": \n" ); document.write( "Length of the box: (x+2)-4 = (x-2) \n" ); document.write( "Width of the box = (x-4) \n" ); document.write( "Height of the box = 2 units \n" ); document.write( ": \n" ); document.write( "Find the area of the bottom of the box \n" ); document.write( "(x-2)*(x-4) = x^2 - 6x + 8 \n" ); document.write( ": \n" ); document.write( "Find the volume (Multiply by the height) given as 70 cu/units \n" ); document.write( "2(x^2 - 6x + 8) = 70 \n" ); document.write( ": \n" ); document.write( "Simplify, divide both sides by 2 \n" ); document.write( "x^2 - 6x + 8 = 35 \n" ); document.write( ": \n" ); document.write( "A quadratic equation: \n" ); document.write( "x^2 - 6x + 8 - 35 = 0 \n" ); document.write( "x^2 - 6x - 27 = 0 \n" ); document.write( ": \n" ); document.write( "Factor this to \n" ); document.write( "(x-9)(x+3) = 0 \n" ); document.write( "; \n" ); document.write( "The positive solution is what we want here: \n" ); document.write( "x = 9 units is the width of the cardboard \n" ); document.write( "then \n" ); document.write( "9 + 2 = 11 units is the length \n" ); document.write( "; \n" ); document.write( ": \n" ); document.write( "Is this true?: \n" ); document.write( "(9-4)(11-4) * 2 = \n" ); document.write( "5 * 7 * 2 = 70 cu/units \n" ); document.write( " |