Answer:
x = 1, y = 2, z = 1
Step-by-step explanation:
Adding the first 2 equations to each other gives
x + y + z + 4x - y - z = 4 + 1
which simplifies to
5x = 5, so x = 1
x + z = 2 so 1 + z = 2, so z = 1 too
x + y + z = 4 = 1 + y + 1 = 2 + y so y = 2
