document.write( "Question 770013: 7c2-3c-4=0 by completing the squares \n" ); document.write( "
Algebra.Com's Answer #469211 by lwsshak3(11628)\"\" \"About 
You can put this solution on YOUR website!
7c2-3c-4=0 by completing the squares
\n" ); document.write( "7c^2-3c-4=0
\n" ); document.write( "complete the square:
\n" ); document.write( "7(c^2-(3/7)c+(9/196)-9/28-4=0
\n" ); document.write( "7(c-(3/14)^2-121/28=0
\n" ); document.write( "divide by 7
\n" ); document.write( "(c-(3/14)^2=121/196
\n" ); document.write( "take sqrt of both sides
\n" ); document.write( "c-3/14=±11/14)
\n" ); document.write( "c=3/14±11/14
\n" ); document.write( "c=(3/14+11/14=14/14=1
\n" ); document.write( "or
\n" ); document.write( "c=(3/14-11/14=-8/14≈-0.571\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );