Question

Solve x + y = 12 and x - y = 4.

Solution

1. Add the two equations to eliminate y: 2x = 16, so x = 8.
2. Substitute x = 8 into x + y = 12: y = 4.
3. Check: 8 - 4 = 4, which is correct.
4. Therefore, x = 8 and y = 4.