document.write( "Question 195102: I have another two questions. This is confusing to me too. please help me. \r
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\n" ); document.write( "\n" ); document.write( "3.) What value should be added to the expression to create a perfect square?
\n" ); document.write( "x2 - 20x \r
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\n" ); document.write( "\n" ); document.write( "4. Solve.
\n" ); document.write( "x2 + 8x 8 = 0
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Algebra.Com's Answer #146334 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "\"x%5E2-20x\" Start with the given expression\r
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\n" ); document.write( "\n" ); document.write( "Now take half of the x coefficient and square it to get \"%28-20%2F2%29%5E2=%28-10%29%5E2=100\". This is the value that you add to the expression to make it a perfect square.\r
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\n" ); document.write( "\n" ); document.write( "So \"x%5E2-20x%2B100\" is a perfect square.\r
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\n" ); document.write( "\n" ); document.write( "Is the equation \"x%5E2%2B8x%2B8=0\" ???\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B8x%2B8=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=8\", and \"c=8\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%288%29+%2B-+sqrt%28+%288%29%5E2-4%281%29%288%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=8\", and \"c=8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+64-4%281%29%288%29+%29%29%2F%282%281%29%29\" Square \"8\" to get \"64\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+64-32+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%288%29\" to get \"32\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+32+%29%29%2F%282%281%29%29\" Subtract \"32\" from \"64\" to get \"32\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+32+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+4%2Asqrt%282%29%29%2F%282%29\" Simplify the square root \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8%29%2F%282%29+%2B-+%284%2Asqrt%282%29%29%2F%282%29\" Break up the fraction. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+-4+%2B-+2%2Asqrt%282%29\" Reduce. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+-4%2B2%2Asqrt%282%29\" or \"x+=+-4-2%2Asqrt%282%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+-4%2B2%2Asqrt%282%29\" or \"x+=+-4-2%2Asqrt%282%29\" \r
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\n" ); document.write( "\n" ); document.write( "which approximate to \"x=-1.172\" or \"x=-6.828\" \r
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\n" ); document.write( "\n" ); document.write( "OR....\r
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\n" ); document.write( "\n" ); document.write( "Is the equation \"x%5E2%2B8x-8=0\" ???\r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2%2B8x-8=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=8\", and \"c=-8\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%288%29+%2B-+sqrt%28+%288%29%5E2-4%281%29%28-8%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=8\", and \"c=-8\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+64-4%281%29%28-8%29+%29%29%2F%282%281%29%29\" Square \"8\" to get \"64\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+64--32+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-8%29\" to get \"-32\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+64%2B32+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%2864--32%29\" as \"sqrt%2864%2B32%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+96+%29%29%2F%282%281%29%29\" Add \"64\" to \"32\" to get \"96\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+sqrt%28+96+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8+%2B-+4%2Asqrt%286%29%29%2F%282%29\" Simplify the square root \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-8%29%2F%282%29+%2B-+%284%2Asqrt%286%29%29%2F%282%29\" Break up the fraction. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+-4+%2B-+2%2Asqrt%286%29\" Reduce. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+-4%2B2%2Asqrt%286%29\" or \"x+=+-4-2%2Asqrt%286%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+-4%2B2%2Asqrt%286%29\" or \"x+=+-4-2%2Asqrt%286%29\" \r
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\n" ); document.write( "\n" ); document.write( "which approximate to \"x=0.899\" or \"x=-8.899\"
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