SOLUTION: Solve the linear system: x+2y= 1 -x+y= -1

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Question 38555: Solve the linear system: x+2y= 1

-x+y= -1
Answer by lyra(94) About Me  (Show Source):
You can put this solution on YOUR website!
Here's two ways to solve your problem:
Solved by pluggable solver: Linear System solver (using determinant)
Solve:
+system%28+%0D%0A++++1%5Cx+%2B+2%5Cy+=+1%2C%0D%0A++++-1%5Cx+%2B+1%5Cy+=+-1+%29%0D%0A++

Any system of equations:
+system%28+%0D%0A++++a%5B11%5D%2Ax+%2B+a%5B12%5D%2Ay+=+b%5B1%5D%2C%0D%0A++++a%5B21%5D%2Ax+%2B+a%5B22%5D%2Ay+=+b%5B2%5D%29%0D%0A++

has solution
+system%28+%0D%0A++++x+=+%28b%5B1%5D%2Aa%5B22%5D+-+b%5B2%5D%2Aa%5B12%5D%29%2F%28a%5B11%5D%2Aa%5B22%5D-a%5B21%5D%2Aa%5B12%5D%29%2C%0D%0A++++y+=+%28a%5B11%5D%2Ab%5B2%5D+-+a%5B21%5D%2Ab%5B1%5D%29%2F%28a%5B11%5D%2Aa%5B22%5D-a%5B21%5D%2Aa%5B12%5D%29%0D%0A++++%29%0D%0A++
or

+system%28+%0D%0A++++++x+=+%281%2A1+-+-1%2A2%29%2F%281%2A1--1%2A2%29+=+1%2C%0D%0A++++++y+=+%281%2A-1+-+-1%2A1%29%2F%281%2A1--1%2A2%29+=+0%0D%0A++++%29%0D%0A++

(x=1, y=0}

Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++1%5Cx+%2B+2%5Cy+=+1%2C%0D%0A++++-1%5Cx+%2B+1%5Cy+=+-1+%29%0D%0A++We'll use substitution. After moving 2*y to the right, we get:
1%2Ax+=+1+-+2%2Ay, or x+=+1%2F1+-+2%2Ay%2F1. Substitute that
into another equation:
-1%2A%281%2F1+-+2%2Ay%2F1%29+%2B+1%5Cy+=+-1 and simplify: Error: 'Can't call method "invoke_solver" on an undefined value at /home/ichudov/project_locations/algebra.com/templates/Algebra/Solver/PerlSolver.pm line 115. Can't call method "invoke_solver" on an undefined value at /home/ichudov/project_locations/algebra.com/templates/Algebra/Solver/PerlSolver.pm line 115. '. Can't call method "invoke_solver" on an undefined value at /home/ichudov/project_locations/algebra.com/templates/Algebra/Solver/PerlSolver.pm line 115. Can't call method "invoke_solver" on an undefined value at /home/ichudov/project_locations/algebra.com/templates/Algebra/Solver/PerlSolver.pm line 115.
error_location: 101


Hope this helps and feel free to contact me with further questions,
lyra