document.write( "Question 353963: I'm a little confused on how to work this one...\r
\n" ); document.write( "\n" ); document.write( "4x^4 - 12x^2 - 19 = 0\r
\n" ); document.write( "\n" ); document.write( "I use subtitution of y = x^2 giving me\r
\n" ); document.write( "\n" ); document.write( "4y^2 - 12y - 19 = 0\r
\n" ); document.write( "\n" ); document.write( "My answers are y = 4.145751311 and -1.145751311\r
\n" ); document.write( "\n" ); document.write( "Now I'm not sure what to do from here.\r
\n" ); document.write( "\n" ); document.write( "Thanks a lot for your help!\r
\n" ); document.write( "\n" ); document.write( "Neil
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Algebra.Com's Answer #253008 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
First, let's solve \"4y%5E2+-+12y+-+19+=+0+\"\r
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\n" ); document.write( "\n" ); document.write( "\"4y%5E2-12y-19=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"4y%5E2-12y-19\" is in the form of \"Ay%5E2%2BBy%2BC\" where \"A=4\", \"B=-12\", and \"C=-19\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for \"y\":\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%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( "\"y+=+%28-%28-12%29+%2B-+sqrt%28+%28-12%29%5E2-4%284%29%28-19%29+%29%29%2F%282%284%29%29\" Plug in \"A=4\", \"B=-12\", and \"C=-19\"\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+%28-12%29%5E2-4%284%29%28-19%29+%29%29%2F%282%284%29%29\" Negate \"-12\" to get \"12\". \r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+144-4%284%29%28-19%29+%29%29%2F%282%284%29%29\" Square \"-12\" to get \"144\". \r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+144--304+%29%29%2F%282%284%29%29\" Multiply \"4%284%29%28-19%29\" to get \"-304\"\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+144%2B304+%29%29%2F%282%284%29%29\" Rewrite \"sqrt%28144--304%29\" as \"sqrt%28144%2B304%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+448+%29%29%2F%282%284%29%29\" Add \"144\" to \"304\" to get \"448\"\r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+sqrt%28+448+%29%29%2F%288%29\" Multiply \"2\" and \"4\" to get \"8\". \r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812+%2B-+8%2Asqrt%287%29%29%2F%288%29\" Simplify the square root (note: If you need help with simplifying square roots, check out this solver) \r
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\n" ); document.write( "\n" ); document.write( "\"y+=+%2812%2B8%2Asqrt%287%29%29%2F%288%29\" or \"y+=+%2812-8%2Asqrt%287%29%29%2F%288%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions in terms of y are \"y+=+%2812%2B8%2Asqrt%287%29%29%2F%288%29\" or \"y+=+%2812-8%2Asqrt%287%29%29%2F%288%29\" \r
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\n" ); document.write( "\n" ); document.write( "But remember that \"y=x%5E2\". So \r
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\n" ); document.write( "\n" ); document.write( "\"x%5E2+=+%2812%2B8%2Asqrt%287%29%29%2F%288%29\" or \"x%5E2+=+%2812-8%2Asqrt%287%29%29%2F%288%29\" \r
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\n" ); document.write( "\n" ); document.write( "Do you think you can take it from here?\r
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\n" ); document.write( "\n" ); document.write( "If you need more help, email me at jim_thompson5910@hotmail.com\r
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\n" ); document.write( "\n" ); document.write( "Also, feel free to check out my tutoring website\r
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\n" ); document.write( "\n" ); document.write( "Jim
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