Question

Given that 4x-y=5 4y-z=7 and 4z-x=18 what is the value of x+y+z

Answer 1

Using simultaneous equations,
x=2, y=3, z=5.

Therefore x+y+z
=2+3+5
=10

Answer 2

x + y +z= 10

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

`\sf (3x)/(3)+(3y)/(3)+(3z)/(3) = (30)/(3)`

x + y + z = 10