document.write( "Question 989590: Hi, I have a problem that deals with linear equations with three variables:
\n" ); document.write( "SOLVE:
\n" ); document.write( "x+y=7
\n" ); document.write( "y+z=8
\n" ); document.write( "x+2z=2\r
\n" ); document.write( "\n" ); document.write( "and no, I cannot simply use matrices to solve this question. I tried eliminating 'z' from the second and third equation, but I got stuck because I can't eliminate 'z' from the first equation. Please help and thank you so much to whoever helps! \n" ); document.write( "

Algebra.Com's Answer #609887 by MathTherapy(10555) $\"\"$ $\"About$

You can put this solution on YOUR website!

\n" ); document.write( "Hi, I have a problem that deals with linear equations with three variables:
\n" ); document.write( "SOLVE:
\n" ); document.write( "x+y=7
\n" ); document.write( "y+z=8
\n" ); document.write( "x+2z=2\r
\n" ); document.write( "\n" ); document.write( "and no, I cannot simply use matrices to solve this question. I tried eliminating 'z' from the second and third equation, but I got stuck because I can't eliminate 'z' from the first equation. Please help and thank you so much to whoever helps!
\n" ); document.write( "

 x + y = 7_____y = 7 - x ------- eq (i)
\n" );
document.write( "    y + z = 8 ------ eq (ii)
\n" );
document.write( "   x + 2z = 2 ------ eq (iii)
\n" );
document.write( "7 - x + z = 8 ------ Substituting 7 - x for y in eq (ii)
\n" );
document.write( "  - x + z = 1 ------ eq (iv)
\n" );
document.write( "       3z = 3 ------ Adding eqs (iv) and (iii)
\n" );
document.write( "        z = , or 
\n" );
document.write( "Complete this by substituting 1 for z in eq (ii) to determine the value of y, and finally, substitute the value of y into eq (i) to get the value of x \n" );
document.write( "

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