document.write( "Question 191751: square root of 2x+11=x+4 Isolate a radical on one side, square both sides, solve the resulting equation \n" ); document.write( "

Algebra.Com's Answer #143888 by RAY100(1637) $\"\"$ $\"About$

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sq rt (2x+11) = (x+4)\r
\n" ); document.write( "\n" ); document.write( "square both sides\r
\n" ); document.write( "\n" ); document.write( "(2x+11) = (x+4)^2 = x^2 +8x +16\r
\n" ); document.write( "\n" ); document.write( "0= x^2 +6x +5\r
\n" ); document.write( "\n" ); document.write( "0 = ( x+5) (x+1)\r
\n" ); document.write( "\n" ); document.write( "x= -5, and x=-1 however\r
\n" ); document.write( "\n" ); document.write( "since we squared we MUST check both answers\r
\n" ); document.write( "\n" ); document.write( "checking x= (-1)\r
\n" ); document.write( "\n" ); document.write( "( 2(-1) +11 ) ^1/2 = ( (-1) + 4 )
\n" ); document.write( "(9)^1/2 =3 =3 ok therefore x= (-1) is valid\r
\n" ); document.write( "\n" ); document.write( "checking x= (-5)\r
\n" ); document.write( "\n" ); document.write( "( 2(-5) +11 )^1/2 = (-5) +4\r
\n" ); document.write( "\n" ); document.write( "(1)^ 1/2 = -1\r
\n" ); document.write( "\n" ); document.write( "1 = -1 questionable \r
\n" ); document.write( "\n" ); document.write( "while (1)^1/2 does equal (+1) and (-1) \r
\n" ); document.write( "\n" ); document.write( "commonly we must question validity of x= (-5) \n" ); document.write( "

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