document.write( "Question 54627: Solve for x: \"sqrt%28x%2B7%29+%2B+sqrt%28x%2B2%29+=+sqrt%28x-1%29+-+sqrt%28x-2%29\"
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\n" ); document.write( "When I solve the above equation, I get x = 2; but when I verify my answer by substituting the value of x in the original equation, it is not matching. I tried a few times to solve using different methods and I am always getting the same value of x as 2. What am I doing wrong?
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Algebra.Com's Answer #36895 by psbhowmick(878)\"\" \"About 
You can put this solution on YOUR website!
\"sqrt%28x%2B7%29+%2B+sqrt%28x%2B2%29+=+sqrt%28x-1%29+-+sqrt%28x-2%29\"
\n" ); document.write( "Squaring both sides
\n" ); document.write( "\"%28sqrt%28x%2B7%29+%2B+sqrt%28x%2B2%29%29%5E2+=+%28sqrt%28x-1%29+-+sqrt%28x-2%29%29%5E2\"
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\n" ); document.write( "\"12+%2B+2%2Asqrt%28x%2B7%29%2Asqrt%28x%2B2%29+=+-+2%2Asqrt%28x-1%29%2Asqrt%28x-2%29\"
\n" ); document.write( "\"6+=+-sqrt%28x%2B7%29%2Asqrt%28x%2B2%29+-+sqrt%28x-1%29%2Asqrt%28x-2%29\"
\n" ); document.write( "Squaring again
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\n" ); document.write( "\"10+=+x%5E2%2B3x+%2B+sqrt%28x%2B7%29%2Asqrt%28x%2B2%29%2Asqrt%28x-1%29%2Asqrt%28x-2%29\"
\n" ); document.write( "\"x%5E2+-+3x+-+10=+-sqrt%28x%2B7%29%2Asqrt%28x%2B2%29%2Asqrt%28x-1%29%2Asqrt%28x-2%29\"
\n" ); document.write( "\"%28x%2B2%29%28x-5%29+=+-sqrt%28x%2B7%29%2Asqrt%28x%2B2%29%2Asqrt%28x-1%29%2Asqrt%28x-2%29\"
\n" ); document.write( "Squaring again
\n" ); document.write( "\"%28x%2B2%29%5E2%28x-5%29%5E2+=+%28x%2B7%29%28x%2B2%29%28x-1%29%28x-2%29\"
\n" ); document.write( "\"%28x%2B2%29%28%28x%2B2%29%28x-5%29%5E2+-+%28x%2B7%29%28x-1%29%28x-2%29%29+=+0\"
\n" ); document.write( "\"%28x%2B2%29%28%28x%2B2%29%28x%5E2+%2B+10x+%2B+25%29+-+%28x%5E2%2B6x-7%29%28x-2%29%29+=+0\"
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\n" ); document.write( "\"%28x%2B2%29%288x%5E2+%2B+64x+%2B+36%29+=+0\"
\n" ); document.write( "\"%28x%2B2%29%282x%5E2+%2B+16x+%2B+9%29+=+0\"\r
\n" ); document.write( "\n" ); document.write( "Clearly no root of this equation is equal to 2. The roots are \"x+=+%28-16+%2B-+sqrt%28+16%5E2-4%2A2%2A9+%29%29%2F%282%2A2%29\" & -2 i.e. \"x+=+-4+%2B-+sqrt%2846%29%2F2\" & -2.\r
\n" ); document.write( "\n" ); document.write( "So all values of the x are negative. So the given equation is no longer valid in real domain.\r
\n" ); document.write( "\n" ); document.write( "Note that the equation is satisfied by x=2 if it is \"sqrt%28x%2B7%29+-+sqrt%28x%2B2%29=...\" and not \"sqrt%28x%2B7%29+%2B+sqrt%28x%2B2%29=...\"
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