Electrostatics. finding the resultant force

[anoel]

anyone can help me out? I've tried but my answer and answer key are differnet!

Homework Statement

three point charges lie on a straight line. find the resultant force exerted on (a) the -2$$\mu$$C charge, (b) the 5 $$\mu$$C charge

1 (5$$\mu$$C) 2(-2$$\mu$$C) 3(3 $$\mu$$C)

distance b/w 1,2 = 2cm
distance b/w 2,3 = 4cm

Homework Equations

k q1 x q2 / distance^2

The Attempt at a Solution

 

[thebigstar25]

please show your attempt even if it was not correct so we can see at which step you have problem ..