document.write( "Question 65696: sqrt2y+7 + 4 = y
\n" ); document.write( "The sqrt is 2y+7\r
\n" ); document.write( "\n" ); document.write( "I am not sure how to work this problem since the equal number is a letter. How would I go about figuring out this equation? \n" ); document.write( "

Algebra.Com's Answer #46407 by funmath(2933) $\"\"$ $\"About$

You can put this solution on YOUR website!
sqrt2y+7 + 4 = y
\n" ); document.write( " $\"sqrt%282y%2B7%29%2B4=y\"$
\n" ); document.write( " $\"sqrt%282y%2B7%29%2B4-4=y-4\"$
\n" ); document.write( " $\"sqrt%282y%2B7%29=y-4\"$
\n" ); document.write( " $\"%28sqrt%282y%2B7%29%29%5E2=%28y-4%29%5E2\"$
\n" ); document.write( " $\"2y%2B7=y%5E2-8y%2B16\"$
\n" ); document.write( " $\"2y-2y%2B7-7=y%5E2-8y-2y%2B16-7\"$
\n" ); document.write( " $\"0=y%5E2-10y%2B9\"$
\n" ); document.write( "0=(y-1)(y-9)
\n" ); document.write( "y-1=0 or y-9=0
\n" ); document.write( "y-1+1=0+1 or y-9+9=0+9
\n" ); document.write( "y=1 or y=9
\n" ); document.write( "Check for extraneous solutions:
\n" ); document.write( "for y=1
\n" ); document.write( " $\"sqrt%282%281%29%2B7%29%2B4=1\"$
\n" ); document.write( " $\"sqrt%289%29%2B4=1\"$
\n" ); document.write( " $\"3%2B4=1\"$
\n" ); document.write( " $\"7=1\"$ False, therefore y=1 is extraneous
\n" ); document.write( "For y=9
\n" ); document.write( " $\"sqrt%282%289%29%2B7%29%2B4=9\"$
\n" ); document.write( " $\"sqrt%2818%2B7%29%2B4=9\"$
\n" ); document.write( " $\"sqrt%2825%29%2B4=9\"$
\n" ); document.write( " $\"5%2B4=9\"$
\n" ); document.write( " $\"9=9\"$ True, y=9 is valid.
\n" ); document.write( "The only true solution is $\"highlight%28y=9%29\"$
\n" ); document.write( "Happy Calculating!!! \n" ); document.write( "

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