document.write( "Question 103589: Find the x-intercepts.
\n" ); document.write( " y = x^2 – 2x – 8
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Algebra.Com's Answer #75308 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
To find the x-intercepts, set the equation equal to zero\r
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\n" ); document.write( "\n" ); document.write( "\"0+=+x%5E2+-+2x+-+8\"\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%5E2-2%2Ax-8=0\" ( notice \"a=1\", \"b=-2\", and \"c=-8\")
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\n" ); document.write( " \"x+=+%28--2+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A-8+%29%29%2F%282%2A1%29\" Plug in a=1, b=-2, and c=-8
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\n" ); document.write( " \"x+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A-8+%29%29%2F%282%2A1%29\" Negate -2 to get 2
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\n" ); document.write( " \"x+=+%282+%2B-+sqrt%28+4-4%2A1%2A-8+%29%29%2F%282%2A1%29\" Square -2 to get 4 (note: remember when you square -2, you must square the negative as well. This is because \"%28-2%29%5E2=-2%2A-2=4\".)
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\n" ); document.write( " \"x+=+%282+%2B-+sqrt%28+4%2B32+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-8%2A1\" to get \"32\"
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\n" ); document.write( " \"x+=+%282+%2B-+sqrt%28+36+%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+=+%282+%2B-+6%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+=+%282+%2B-+6%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+=+%282+%2B+6%29%2F2\" or \"x+=+%282+-+6%29%2F2\"
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\n" ); document.write( " Lets look at the first part:
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\n" ); document.write( " \"x=%282+%2B+6%29%2F2\"
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\n" ); document.write( " \"x=8%2F2\" Add the terms in the numerator
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\n" ); document.write( " \"x=4\" Divide
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\n" ); document.write( " So one answer is
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\n" ); document.write( " \"x=4\"
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\n" ); document.write( " Now lets look at the second part:
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\n" ); document.write( " \"x=%282+-+6%29%2F2\"
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\n" ); document.write( " \"x=-4%2F2\" Subtract the terms in the numerator
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\n" ); document.write( " \"x=-2\" Divide
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\n" ); document.write( " So another answer is
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\n" ); document.write( " \"x=-2\"
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\n" ); document.write( " So our solutions are:
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\n" ); document.write( " \"x=4\" or \"x=-2\"
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