document.write( "Question 215290This question is from textbook Higher GCSE Mathematics for Edexcel
\n" ); document.write( ": please can you explain how to find the solution to the quadratic equation with brackets in
\n" ); document.write( "x(2x+5)=10
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Algebra.Com's Answer #162675 by jim_thompson5910(35256)\"\" \"About 
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\"x%282x%2B5%29=10\" Start with the given equation.
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2%2B5x=10\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"2x%5E2%2B5x-10=0\" Subtract 10 from both sides.\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=2\", \"b=5\", and \"c=-10\"\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-%285%29+%2B-+sqrt%28+%285%29%5E2-4%282%29%28-10%29+%29%29%2F%282%282%29%29\" Plug in \"a=2\", \"b=5\", and \"c=-10\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+25-4%282%29%28-10%29+%29%29%2F%282%282%29%29\" Square \"5\" to get \"25\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+25--80+%29%29%2F%282%282%29%29\" Multiply \"4%282%29%28-10%29\" to get \"-80\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+25%2B80+%29%29%2F%282%282%29%29\" Rewrite \"sqrt%2825--80%29\" as \"sqrt%2825%2B80%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+105+%29%29%2F%282%282%29%29\" Add \"25\" to \"80\" to get \"105\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5+%2B-+sqrt%28+105+%29%29%2F%284%29\" Multiply \"2\" and \"2\" to get \"4\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-5%2Bsqrt%28105%29%29%2F%284%29\" or \"x+=+%28-5-sqrt%28105%29%29%2F%284%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+%28-5%2Bsqrt%28105%29%29%2F%284%29\" or \"x+=+%28-5-sqrt%28105%29%29%2F%284%29\" \r
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\n" ); document.write( "\n" ); document.write( "which approximate to \"x=1.312\" or \"x=-3.812\"
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