document.write( "Question 65430This question is from textbook An Incremental Development
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document.write( ": Solve by completing the square\r
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document.write( "3x^2 - 4x + 5 = 0 \n" );
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Algebra.Com's Answer #46050 by ptaylor(2198)![]() ![]() You can put this solution on YOUR website! Solve by completing the square\r \n" ); document.write( "\n" ); document.write( "3x^2 - 4x + 5 = 0 \r \n" ); document.write( "\n" ); document.write( "First, divide both sides by 3. (We want the coefficient of x^2 to be 1. This will simplify completing the square). We get:\r \n" ); document.write( "\n" ); document.write( "x^2-(4/3)x+(5/3)=0\r \n" ); document.write( "\n" ); document.write( "Next, subtract (5/3) from both sides. This removes the \"C\" term from the left side. We will now choose another \"C\" term that will result in a perfect square on the left side and then we will add it to both sides:\r \n" ); document.write( "\n" ); document.write( "x^2-(4/3)x=-(5/3)\r \n" ); document.write( "\n" ); document.write( "Now, we will complete the square. Take half of the \"x\" coefficient (1/2)(4/3), square it ((1/2)(4/3))^2 and add it to both sides: \n" ); document.write( "((1/2)(4/3))^2=(4/6)^2=16/36 so we add 16/36 to both sides:\r \n" ); document.write( "\n" ); document.write( "x^2-(4/3)x+(16/36)=-(5/3)+(16/36)\r \n" ); document.write( "\n" ); document.write( "Let's simplify the right side of the equation \n" ); document.write( "-(5/3)+(16/36)=-(60/36)+(16/36)=-44/36\r \n" ); document.write( "\n" ); document.write( "Note: the left side is a perfect square: \n" ); document.write( "(x-4/6)^2=-44/36\r \n" ); document.write( "\n" ); document.write( "Take sqrt of both sides: \n" ); document.write( "x-4/6=+or-sqrt(-44/36) add 4/6 to both sides:\r \n" ); document.write( "\n" ); document.write( "x=(4/6)+or-((i)sqrt(44))/6 simplifying: \n" ); document.write( "x=(4+or-((i)sqrt(4)(11)))6 and this equals \n" ); document.write( "x=(4+or-(2i)sqrt(11))/6 or \n" ); document.write( "x=(2+(i)sqrt(11))/2 \n" ); document.write( "x=(2-(i)sqrt(11))/2\r \n" ); document.write( "\n" ); document.write( "Happy holidays----ptaylor\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |