SOLUTION: Solve the system by addition. 3x + 2y = –18 x + 4y = 14

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Question 82406: Solve the system by addition.
3x + 2y = –18
x + 4y = 14

Answer by jim_thompson5910(21667) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: Linear Systems by Addition
We'll solve the system:
3%2Ax+%2B+2%2Ay+=+-18
1%2Ax+%2B+4%2Ay+=+14
by elimination by addition.To eliminate by addition, we need to set both coefficients of x to numbers with changed signs, i.e a and -a. Since in the second equation we have 1 as our coefficient for x, to get -3 we have to multiply all terms of the second equation by -3%2F1 which is equal to -3.

Multiplying, we get on our second equation:%281%2A-3%29x+%2B+%284%2A-3%29y+=+14%2A-3
-3%2Ax+%2B+-12%2Ay+=+-42

Adding both equations we get:

%283%2B-3%29x+%2B+%282%2B-12%29y+=+%28-18%2B-42%29

Since 3 and -3 cancel out, we have a linear equation: 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