document.write( "Question 103833: square root 7x+29=x+3 \n" ); document.write( "
Algebra.Com's Answer #75492 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\"sqrt%287x%2B29%29=x%2B3\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"7x%2B29=%28x%2B3%29%5E2\" Square both sides\r
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\n" ); document.write( "\n" ); document.write( "\"7x%2B29=x%5E2%2B6x%2B9\" Foil\r
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\n" ); document.write( "\n" ); document.write( "\"0=x%5E2-x-20\" Get all terms to one side\r
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Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:

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\n" ); document.write( " Starting with the general quadratic
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\n" ); document.write( " \"ax%5E2%2Bbx%2Bc=0\"
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\n" ); document.write( " the general solution using the quadratic equation is:
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\n" ); document.write( " \"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29\"
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\n" ); document.write( " So lets solve \"x%5E2-x-20=0\" ( notice \"a=1\", \"b=-1\", and \"c=-20\")
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\n" ); document.write( " \"x+=+%28--1+%2B-+sqrt%28+%28-1%29%5E2-4%2A1%2A-20+%29%29%2F%282%2A1%29\" Plug in a=1, b=-1, and c=-20
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\n" ); document.write( " \"x+=+%281+%2B-+sqrt%28+%28-1%29%5E2-4%2A1%2A-20+%29%29%2F%282%2A1%29\" Negate -1 to get 1
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\n" ); document.write( " \"x+=+%281+%2B-+sqrt%28+1-4%2A1%2A-20+%29%29%2F%282%2A1%29\" Square -1 to get 1 (note: remember when you square -1, you must square the negative as well. This is because \"%28-1%29%5E2=-1%2A-1=1\".)
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\n" ); document.write( " \"x+=+%281+%2B-+sqrt%28+1%2B80+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-20%2A1\" to get \"80\"
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\n" ); document.write( " \"x+=+%281+%2B-+sqrt%28+81+%29%29%2F%282%2A1%29\" Combine like terms in the radicand (everything under the square root)
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\n" ); document.write( " \"x+=+%281+%2B-+9%29%2F%282%2A1%29\" Simplify the square root (note: If you need help with simplifying the square root, check out this solver)
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\n" ); document.write( " \"x+=+%281+%2B-+9%29%2F2\" Multiply 2 and 1 to get 2
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\n" ); document.write( " So now the expression breaks down into two parts
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\n" ); document.write( " \"x+=+%281+%2B+9%29%2F2\" or \"x+=+%281+-+9%29%2F2\"
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\n" ); document.write( " Lets look at the first part:
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\n" ); document.write( " \"x=%281+%2B+9%29%2F2\"
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\n" ); document.write( " \"x=10%2F2\" Add the terms in the numerator
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\n" ); document.write( " \"x=5\" Divide
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\n" ); document.write( " So one answer is
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\n" ); document.write( " \"x=5\"
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\n" ); document.write( " Now lets look at the second part:
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\n" ); document.write( " \"x=%281+-+9%29%2F2\"
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\n" ); document.write( " \"x=-8%2F2\" Subtract the terms in the numerator
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\n" ); document.write( " \"x=-4\" Divide
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\n" ); document.write( " So another answer is
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\n" ); document.write( " \"x=-4\"
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\n" ); document.write( " So our solutions are:
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\n" ); document.write( " \"x=5\" or \"x=-4\"
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\n" ); document.write( "\n" ); document.write( "Now let's plug in our possible answers back in to check\r
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\n" ); document.write( "\n" ); document.write( "Let's check the answer x=-4\r
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\n" ); document.write( "\n" ); document.write( "\"sqrt%287x%2B29%29=x%2B3\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"sqrt%287%28-4%29%2B29%29=-4%2B3\" Plug in \"x=-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"1=-1\" Simplify. Since this is not true, x=-4 is not a solution\r
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\n" ); document.write( "\n" ); document.write( "Now let's check the answer x=5\r
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\n" ); document.write( "\n" ); document.write( "\"sqrt%287x%2B29%29=x%2B3\" Start with the given equation\r
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\n" ); document.write( "\n" ); document.write( "\"sqrt%287%285%29%2B29%29=5%2B3\" Plug in \"x=5\"\r
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\n" ); document.write( "\n" ); document.write( "\"8=8\" Simplify. Since this is true, x=5 is a solution\r
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\n" ); document.write( "\n" ); document.write( "So our only solution is x=5
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