б) {5x-2y=0, x+2y=12}

1. Add the two equations together: (5x - 2y) + (x + 2y) = 0 + 12 => 6x = 12.
2. Solve for x: x = 2.
3. Substitute x=2 into the second equation: 2 + 2y = 12 => 2y = 10 => y = 5.
Answer: x=2, y=5