document.write( "Question 919925: If f(x) = x^5 + Ax^2 - 2Ax + 2 and f(-1) = 4, find f(1). \n" ); document.write( "
Algebra.Com's Answer #558075 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
your equation is:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(x) = x^5 + ax^2 - 2ax + 2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "you also know that f(-1) = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "replace x with -1 in your original equation and you get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = (-1)^5 + a(-1)^2 - 2a(-1) + 2 which becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = -1 + a + 2a + 2 which becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = 3a + 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "since f(-1) = 4, this means that:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3a + 1 = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "subtract 1 from both sides of that equation to get:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3a = 3 which results in:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "a = 1\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "that's your solution.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "to confirm, replace a in the original equation with 1.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "the original equation becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "x^5 + x^2 - 2x + 2\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = (-1)^5 + (-1)^2 - 2(-1) + 2 which becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = -1 + 1 + 2 + 2 which becomes:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "f(-1) = 4\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "this agrees with what you were given that f(-1) = 4, so the solution of a = 1 is good.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );