Algebra-1

Question Analysis
This question tests the student's ability to solve a system of linear equations using the elimination method and then find the sum of the solution values.

Key Concept Explanation
The elimination method involves adding or subtracting the equations to eliminate one of the variables, solving for the remaining variable, and then substituting back to find the other variable.

Step-by-step Solution
1. Observe the coefficients of the variables in the given system: and .
2. To eliminate , multiply the second equation by 2: .
3. Subtract the first equation from this new equation: .
4. Simplify: , so .
5. Substitute