document.write( "Question 102860: PLEASE HELP ME WITH THIS!!
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document.write( "IF THE LENGTH OF THE SIDE OF A SQUARE IS INCREASED BY 6 UNITS, THE AREA IS MULTIPLIED BY 4. FIND THE ORIGINAL LENGTH. \n" );
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Algebra.Com's Answer #74817 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! If you call the side of the original square x, then the area of the original square is x^2. \n" ); document.write( ". \n" ); document.write( "Now increase the length of each side by 6 units. So each side of the new square is x + 6. \n" ); document.write( "This means that the area of this new square Bis (x + 6)^2 which multiplies out to x^2 + 12x + 36. \n" ); document.write( ". \n" ); document.write( "But the area new square is 4 times the area of the old square ... or 4x^2. So set the area \n" ); document.write( "of the new square equal to 4 times the area of the old square. In equation form this is \n" ); document.write( ". \n" ); document.write( "x^2 + 12x + 36 = 4x^2 \n" ); document.write( ". \n" ); document.write( "To put this into a more standard form, subtract 4x^2 from both sides to get: \n" ); document.write( ". \n" ); document.write( "-3x^2 + 12x + 36 = 0 \n" ); document.write( ". \n" ); document.write( "Note that -3 is a factor of all terms on the left side. Therefore you can simplify \n" ); document.write( "this equation by dividing both sides (all terms) by -3 to reduce the equation to: \n" ); document.write( ". \n" ); document.write( "x^2 - 4x - 12 = 0 \n" ); document.write( ". \n" ); document.write( "Factor the left side to get: \n" ); document.write( ". \n" ); document.write( "(x - 6)(x + 2) = 0 \n" ); document.write( ". \n" ); document.write( "Notice this equation is true if either of the two factors on the left side equals zero. \n" ); document.write( "So set each factor equal to zero and solve for x. \n" ); document.write( ". \n" ); document.write( "x - 6 = 0 ... add 6 to both sides to get x = 6. This is one possible answer. \n" ); document.write( ". \n" ); document.write( "x + 2 = 0 ... subtract 2 from both sides to get x = -2 ... another possible answer. \n" ); document.write( ". \n" ); document.write( "But having a side of square equal to -2 doesn't make any sense. So the only reasonable answer \n" ); document.write( "is that x ... the side of the original square ... is 6. \n" ); document.write( ". \n" ); document.write( "Let's check the answer. If the sides of the original square are 6 units, then the area of \n" ); document.write( "the original square is 6 times 6 or 36 square units. \n" ); document.write( ". \n" ); document.write( "Increasing each side of the original square by 6 units makes the new square have sides of \n" ); document.write( "12 units. Therefore, the area of the new square is 12 times 12 or 144 square units. \n" ); document.write( "Notice that the area of the new square is 4 times the area of the original square ... \n" ); document.write( "4 times 36 equals 144 square units. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to understand the problem. \n" ); document.write( ". \n" ); document.write( " |