document.write( "Question 636581: Solve the system by using substitue or elimination method.
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document.write( "2w+x-3y=19
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document.write( "3w-x-3y-2z=14
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document.write( "w-2x-y-2z=-2
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document.write( "-2w+2x+3y+z=-7 \n" );
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Algebra.Com's Answer #401122 by DrBeeee(684)![]() ![]() ![]() You can put this solution on YOUR website! (1) 2w + x - 3y + 0 = 19 \n" ); document.write( "(2) 3w - x - 3y - 2z = 14 \n" ); document.write( "(3) w - 2w - y - 2z = -2 \n" ); document.write( "(4)-2w + 2x + 3y + z = -7 \n" ); document.write( "To solve, the simplist method (used by most computer algorithms) is elimination.\r \n" ); document.write( "\n" ); document.write( "Using (3) as the \"anchor\" polynomial we can eliminate w in each of the other three by performing the following operations; \n" ); document.write( "(1) - 2*(3) yields (5) 5x - y + 4z = 23 \n" ); document.write( "(2) - 3*(3) yields (6) 5x + 4z = 20 \n" ); document.write( "(4) + 2*(3) yields (7)-2x + y - 3z = -11\r \n" ); document.write( "\n" ); document.write( "Substituting (6) into (5) yields the value of the variable y; \n" ); document.write( " y = -3 \n" ); document.write( "Now let y = -3 in (7) to result with \n" ); document.write( "(7)' -2x - 3z = -8 \n" ); document.write( "Using (7)' and (6) we have \n" ); document.write( " -2x - 3z = -8 and \n" ); document.write( " 5x + 4z = 20 \n" ); document.write( "The simultation solution of this pair is \n" ); document.write( " x = 4 \n" ); document.write( " z = 0 \n" ); document.write( "Substitute the derived values of x, y, and z into (1) yields \n" ); document.write( " 2w + 4 - 3*(-3) = 19 \n" ); document.write( " 2w = 6 \n" ); document.write( " w = 3 \n" ); document.write( "Are the values correct? \n" ); document.write( "Substitute each into the four given equations and see if we get equality. \n" ); document.write( "Is (6+4+9+0=19? yes \n" ); document.write( "Is (9-4+9+0=14)? Yes \n" ); document.write( "Is (3-8+3+0=-2)? Yes \n" ); document.write( "Is (-6+8-9+0=-7)? Yes\r \n" ); document.write( "\n" ); document.write( "The answer is w = 3, x = 4, y = -3 and z = 0 \n" ); document.write( " \n" ); document.write( " |