document.write( "Question 1105538: If a-b=-4 and a+c=4, find the value of $\"+2a%5E2-b%5E2-c%5E2+\"$ \n" ); document.write( "

Algebra.Com's Answer #720389 by ikleyn(52909) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "

\r\n" );
document.write( "1.  a - b = -4    (1)\r\n" );
document.write( "    a + c =  4    (2)\r\n" );
document.write( "\r\n" );
document.write( "               ==================>  subtract (1) from (2) to get\r\n" );
document.write( "\r\n" );
document.write( "    c + b = 8.    (3)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "2.   =  +  = \r\n" );
document.write( "\r\n" );
document.write( "    = (a-b)*(a+b) + (a-c)*(a+c) =  (replace here a-b  with -4  in accordance with (1) )\r\n" );
document.write( "                                   (replace      a+c  with  4  in accordance with (2) )\r\n" );
document.write( "\r\n" );
document.write( "    = -4*(a+b) +4*(a-c) = 4*(a -c - a - b) = = -4*(c + b)  =  (replace here c+b  with 8  in accordance with (3) )\r\n" );
document.write( "\r\n" );
document.write( "    = -4*8 = -32.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );