Answer:
x + y +z= 10
Step-by-step explanation:
4x - y = 5 ---------(I)
4y - z = 7 ---------(II)
4z - x = 18 ---------(III)
Add all the three equations,
4x - y + 4y - z + 4z - x = 5 + 7 + 18
4x - x -y + 4y -z + 4z = 30
3x + 3y + 3z = 30
Divide the entire equation by 3
[tex]\sf \dfrac{3x}{3}+\dfrac{3y}{3}+\dfrac{3z}{3} = \dfrac{30}{3}[/tex]
x + y + z = 10
