document.write( "Question 164189: solve the system:
\n" ); document.write( "5x-3y+z=-7
\n" ); document.write( "4x+5y+3z=-2
\n" ); document.write( "2x-3y+5z=22
\n" ); document.write( "show work and i think you can solve it in the calculator by matrices right?
\n" ); document.write( "if you know both ways please show thanks!
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #121996 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
solve the system:
\n" ); document.write( "5x-3y+z=-7
\n" ); document.write( "4x+5y+3z=-2
\n" ); document.write( "2x-3y+5z=22
\n" ); document.write( "show work and i think you can solve it in the calculator by matrices right?
\n" ); document.write( "if you know both ways please show thanks!
\n" ); document.write( "-------------------
\n" ); document.write( "You can do it by elimination and substitution, but that's tedious and error prone.
\n" ); document.write( "If you calculator has the functionality, you can do a matrix solution on it.
\n" ); document.write( "I have an Excel sheet that does it using determinants.
\n" ); document.write( "By Excel:
\n" ); document.write( "x = -3
\n" ); document.write( "y = -1
\n" ); document.write( "z = +5
\n" ); document.write( "-----------
\n" ); document.write( "Using elimination and substitution:
\n" ); document.write( "5x-3y+z=-7 eqn 1
\n" ); document.write( "4x+5y+3z=-2 eqn 2
\n" ); document.write( "2x-3y+5z=22 eqn 3
\n" ); document.write( "------------
\n" ); document.write( "Eqn 1 has a z coeff of 1, so muliply it by 3, and then by 5.
\n" ); document.write( "5x-3y+z=-7
\n" ); document.write( "15x - 9y + 3z = -21 eqn 1 times 3
\n" ); document.write( " 4x + 5y + 3z = -2 eqn 2
\n" ); document.write( "11x - 14y = -19 Subtract eqn 2
\n" ); document.write( "----------------
\n" ); document.write( "5x-3y+z=-7 eqn 1 again
\n" ); document.write( "25x - 15y + 5z = -35 eqn 1 times 5
\n" ); document.write( " 2x - 3y + 5z = 22 eqn 3
\n" ); document.write( "23x - 12y = -57 Subract eqn 3
\n" ); document.write( "-------------
\n" ); document.write( "Now there are 2 eqns in 2 unknowns (x and y)
\n" ); document.write( "11x - 14y = -19
\n" ); document.write( "23x - 12y = -57
\n" ); document.write( "Multiply the 1st times 6, and the 2nd times 7 to get the same coeff for y.
\n" ); document.write( "66x - 84y = -114
\n" ); document.write( "161x -84y = -399 Subtract
\n" ); document.write( "-95x = 285
\n" ); document.write( "x = -3
\n" ); document.write( "------------
\n" ); document.write( "Sub into 11x - 14y = -19 to get
\n" ); document.write( "y = -1
\n" ); document.write( "-----------
\n" ); document.write( "Sub x and y into any of the original 3 eqns to get
\n" ); document.write( "z = +5\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );