document.write( "Question 3585: I need help
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document.write( "(x^2+2x)^2-5(x^2+2x)+6=0\r
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document.write( " and\r
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document.write( "x^1/2-11x^1/4+30\r
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document.write( " and\r
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document.write( "6x^3/5-24=0 \n" );
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Algebra.Com's Answer #1597 by khwang(438)![]() ![]() ![]() You can put this solution on YOUR website! (I) (x^2+2x)^2-5(x^2+2x)+6=0 \n" ); document.write( " Let y = x^2+2x, then the given equation is converted to \n" ); document.write( " y^2 - 5y + 6 =0, \n" ); document.write( " Factor: (y-2)(y-3) = 0 \n" ); document.write( " so, y= 2 or 3. \n" ); document.write( " That is, x^2+2x = 2 or x^2+2x = 3, \n" ); document.write( " Hence x^2+2x - 2 = 0, \n" ); document.write( " By quadratic formula, x= -1 + sqrt(3) or -1 - sqrt(3) \n" ); document.write( " Or x^2+2x - 3 = 0, \n" ); document.write( " Factor: (x-1)(x+3) =0, so x = 1 or -3 [Four solutions of x]\r \n" ); document.write( "\n" ); document.write( " (II) x^1/2-11x^1/4+30 \n" ); document.write( " Let u = x^1/4, then we have \n" ); document.write( " u^2 - 11 u + 30 = 0, \n" ); document.write( " Factor: (u-6)(u-5) =0, so u = 6 or 5. \n" ); document.write( " When u=6 , x^1/4 = 6, x = 6^4 = 36^2 = 1296 \n" ); document.write( " When u=5 , x^1/4 = 5, x = 5^4 = 25^2 = 625.\r \n" ); document.write( "\n" ); document.write( " (III) 6x^3/5-24=0 \n" ); document.write( " Cancel 6: x^3/5-4=0, \n" ); document.write( " Or x^3/5 = 4 \n" ); document.write( " So, x = 4^(5/3) = 4 * 4^(2/3) = 4 * (2^4)^(1/3) \n" ); document.write( " = 4*2 * 2^(1/3) = 8* 2^(1/3) \n" ); document.write( " \n" ); document.write( " Try to check the above answers yourself.\r \n" ); document.write( "\n" ); document.write( " Kenny \n" ); document.write( " |