document.write( "Question 368794: solve $\"sqrt%287x%2B36%29\"$ =x+4 \n" ); document.write( "

Algebra.Com's Answer #262744 by fractalier(6550) $\"\"$ $\"About$

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From $\"sqrt%287x%2B36%29=x%2B4\"$
\n" ); document.write( "let us square both sides and get
\n" ); document.write( " $\"7x+%2B+36+=+x%5E2+%2B+8x+%2B+16\"$
\n" ); document.write( "Now collect terms and get
\n" ); document.write( " $\"x%5E2+%2B+x+-+20+=+0\"$ (Notice I flipped it)
\n" ); document.write( "Now factor and solve
\n" ); document.write( " $\"%28x+%2B+5%29%28x+-+4%29+=+0\"$
\n" ); document.write( "and
\n" ); document.write( "x = -5 or x = 4
\n" ); document.write( "For problems involving roots, YOU HAVE TO CHECK solutions.
\n" ); document.write( "Notice x = 4 works fine but x = -5 does not. \n" ); document.write( "

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