document.write( "Question 154171This question is from textbook elementary and intermediate algebra concepts and applications
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\n" ); document.write( "\n" ); document.write( "2. What three techniques can be used to solve a quadratic equation? Demonstrate these techniques on the equation \"12x2 - 10x - 42 = 0\".\r
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Algebra.Com's Answer #113476 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
You can solve by 1) factoring, 2) quadratic formula, and 3) completing the square. I'll do the second technique to get you started\r
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\n" ); document.write( "\n" ); document.write( "\"12x%5E2-10x-42=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=12\", \"b=-10\", and \"c=-42\"\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-%28-10%29+%2B-+sqrt%28+%28-10%29%5E2-4%2812%29%28-42%29+%29%29%2F%282%2812%29%29\" Plug in \"a=12\", \"b=-10\", and \"c=-42\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+%28-10%29%5E2-4%2812%29%28-42%29+%29%29%2F%282%2812%29%29\" Negate \"-10\" to get \"10\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+100-4%2812%29%28-42%29+%29%29%2F%282%2812%29%29\" Square \"-10\" to get \"100\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+100--2016+%29%29%2F%282%2812%29%29\" Multiply \"4%2812%29%28-42%29\" to get \"-2016\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+100%2B2016+%29%29%2F%282%2812%29%29\" Rewrite \"sqrt%28100--2016%29\" as \"sqrt%28100%2B2016%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+2116+%29%29%2F%282%2812%29%29\" Add \"100\" to \"2016\" to get \"2116\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+sqrt%28+2116+%29%29%2F%2824%29\" Multiply \"2\" and \"12\" to get \"24\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B-+46%29%2F%2824%29\" Take the square root of \"2116\" to get \"46\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2810+%2B+46%29%2F%2824%29\" or \"x+=+%2810+-+46%29%2F%2824%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2856%29%2F%2824%29\" or \"x+=++%28-36%29%2F%2824%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+7%2F3\" or \"x+=+-3%2F2\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+7%2F3\" or \"x+=+-3%2F2\" \r
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