Electric charge/Colombs law problems

[RandellK02]

I have a problem I am working on before the end of today and I am having some trouble getting the right answer. What am I missing?

1.

Homework Statement

The charges and coordinates of two charged particles held fixed in an xy plane are q1 = 3.11 μC, x1 = 5.72 cm, y1 = 0.703 cm and q2 = -6.23 μC, x2 = -1.59 cm, y2 = 2.45 cm. At what (a)x and (b)y coordinates should a third particle of charge q3 = 5.06 μC be placed such that the net electrostatic force on particle 2 due to particles 1 and 3 is zero?

Homework Equations

k=qQ/r^2

The Attempt at a Solution

q₁=3.1 E-6 x:0.0572 m y:0.00703 m
q₂=-6.23 E-6 x:-0.0159 y:0.0245 m
q₃=5.06 E-6

First I find F_1,2 for the x component:
F_1,2x=kq₁q₂/d²
note:d=-0.0159 - 0.0572

Next I conclude for equilibrium @q₂ q_1x=q_3x. Same for y component.

So to find X of q₃...
F_1,3x ==> F_1,2x= kq₁q₃/x²

I assumed solving for X will give me the answer but its incorrect...
Similar process for the y component.

 

[1994Bhaskar]

A thing to say--There's a much shorter method for this.You know the center of mass of system is point where all forces due to mass is zero.Same we can apply here as center of charge(though this method works BUT IT IS NOT OFFICIAL.DON'T USE THIS IN YOUR EXAMS) with same formula as center of mass just by replacing mass by charge(m1 by q1).