Electrostatics and work question

[IState21]

Homework Statement

Determine the amount of work needed to transfer two charges of 40nC and -50nC from infinity to locations (0,0,1) and (2,0,0) respectively.

I got an answer but it doesn't seem right

Homework Equations

Used in attempt

The Attempt at a Solution

W=(1/(4∏ε))*((40n*-50n)/(mag((2,0,0)-(0,0,1)))
W=-8.05 μN

 

[zhermes]

formula is right, assuming you did the math correctly its good. Is that what you need checked?