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Solve the system of linear equations with three variables.

$x + y + z = 15$$2x + y = 15$$z = 5$

$x = 5, y = 5, z = 5$

$x = 7, y = 3, z = 5$

$x = 1, y = 9, z = 5$

$x = 2, y = 8, z = 5$