document.write( "Question 199679: please help me solve and graph this equation: 5x^2-20x-60=0 \n" ); document.write( "
Algebra.Com's Answer #150054 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\"5x%5E2-20x-60=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic in the form of \"Ax%5E2%2BBx%2BC\" where \"A=5\", \"B=-20\", and \"C=-60\"\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-%28-20%29+%2B-+sqrt%28+%28-20%29%5E2-4%285%29%28-60%29+%29%29%2F%282%285%29%29\" Plug in \"A=5\", \"B=-20\", and \"C=-60\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+%28-20%29%5E2-4%285%29%28-60%29+%29%29%2F%282%285%29%29\" Negate \"-20\" to get \"20\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+400-4%285%29%28-60%29+%29%29%2F%282%285%29%29\" Square \"-20\" to get \"400\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+400--1200+%29%29%2F%282%285%29%29\" Multiply \"4%285%29%28-60%29\" to get \"-1200\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+400%2B1200+%29%29%2F%282%285%29%29\" Rewrite \"sqrt%28400--1200%29\" as \"sqrt%28400%2B1200%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+1600+%29%29%2F%282%285%29%29\" Add \"400\" to \"1200\" to get \"1600\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+sqrt%28+1600+%29%29%2F%2810%29\" Multiply \"2\" and \"5\" to get \"10\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B-+40%29%2F%2810%29\" Take the square root of \"1600\" to get \"40\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2820+%2B+40%29%2F%2810%29\" or \"x+=+%2820+-+40%29%2F%2810%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2860%29%2F%2810%29\" or \"x+=++%28-20%29%2F%2810%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+6\" or \"x+=+-2\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the solutions are \"x+=+6\" or \"x+=+-2\" \r
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