document.write( "Question 406079: Use the following quadratic equation to complete parts a and b below. You must show all work.\r
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document.write( "x2 + 4x - 21 = 0\r
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document.write( "a. Solve by factoring.
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document.write( "b. Solve using the quadratic formula. \n" );
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Algebra.Com's Answer #286656 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! x^2 + 4x - 21 = 0 \n" ); document.write( "a. Solve by factoring. \n" ); document.write( "x^2+7x-3x-21 = 0 \n" ); document.write( "x(x+7)-3(x+7) = 0 \n" ); document.write( "(x+7)(x-3) = 0 \n" ); document.write( "x = -7 or x = 3 \n" ); document.write( "============================================= \n" ); document.write( "b. Solve using the quadratic formula. \n" ); document.write( "x = [-4 +- sqrt(16 - 4*1*-21)]/2 \n" ); document.write( "--- \n" ); document.write( "x = [-4 +- sqrt(16+84)]/2 \n" ); document.write( "--- \n" ); document.write( "x = [-4 +- 10]/2 \n" ); document.write( "--- \n" ); document.write( "x = [-2+- 5] \n" ); document.write( "--- \n" ); document.write( "x = -7 or x = 3\r \n" ); document.write( "\n" ); document.write( "=================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( "=============== \n" ); document.write( " |