document.write( "Question 1209868: If 2^{16^x} = 128*4^x, then find 2^x. \n" ); document.write( "
Algebra.Com's Answer #850937 by ikleyn(52776)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "If 2^{16^x} = 128*4^x, then find 2^x.
\n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\r\n" );
document.write( "Your starting equation is\r\n" );
document.write( "\r\n" );
document.write( "    2^{16^x} = 128*4^x.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Notice that 2^(16^x) = 2^(2^(4x)).  \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So, the original equation is equivalent to \r\n" );
document.write( "\r\n" );
document.write( "    2^(2^(4x)) = 2^7 * 2^(2x).\r\n" );
document.write( "\r\n" );
document.write( " \r\n" );
document.write( "It implies for indexes\r\n" );
document.write( "\r\n" );
document.write( "    2^(4x) = 2x + 7.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "This equation can not be solved algebraically, but it can be solved approximately \r\n" );
document.write( "with reasonable precision using numerical methods and special solvers in the Internet.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "I used online solver at the site www.desmos.com/calculator. The calculator produced two approximate solutions\r\n" );
document.write( "\r\n" );
document.write( "    \"x%5B1%5D\" = -3.49997  (approximately),  and   \"x%5B2%5D\" = 0.77389  (approximately)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "            As the reference to the solver' solution, see this link\r\n" );
document.write( "\r\n" );
document.write( "            https://www.desmos.com/calculator/tmxp2wpqt3\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Therefore, \"2%5Ex\"  may have two values\r\n" );
document.write( "\r\n" );
document.write( "    \"2%5E%28-3.49997%29\" = 0.08839  (approx.)  and   \"2%5E0.77389\" = 1.709874 (approx.)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "These values, \"x%5B1%5D\" = 0.08838  and  \"x%5B2%5D\" = 1.709874,  are your ANSWER  to the problem's question.\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" ); document.write( "
\n" );