Electric Potential & Electric Field

[scrubber]

Homework Statement

Three positive charges lie on the x-axis; q1 = 15 μC is at the origin, q2 = -30 μC is at x = 2 m, and q3 = 15 μC is a x = 3 m. ( please also refer to the attachment.)
Find the electric potential and electric field at point “P” aroused from q1, q2 and q3.

The Attempt at a Solution

The suggested answer is attached.
But I don't understand why q1 is also counted in both answers, and why the corresponding distance(r) is 1.

So weird to me... please help!

 

[amind]

From the solution given , it seems that the point $P$ is at $x=1$ distance , that would make the eqⁿs
consistent.

P.S Please write the solutions and/or any other equations in your post preferably using LaTeX as it can be difficult to read equations from the image and/or quoting them.

 

[scrubber]

From the solution given , it seems that the point $P$ is at $x=1$ distance , that would make the eqⁿs
consistent.

P.S Please write the solutions and/or any other equations in your post preferably using LaTeX as it can be difficult to read equations from the image and/or quoting them.

great! I understand now! Sorry for the inconvenience. I will type them out next time. Thanks for your help :D