Electric field strength at a point between charges

[Ch3m_]

Homework Statement

A +1.0 μC charge is placed at point X. A +4.0 μC charge is placed at point Y,
50 cm from X.
How far from X, on the line XY, is the point where the electric field strength is zero?

Homework Equations

E = Q/4πε₀r²

The Attempt at a Solution

I know that the electric field is zero at the point where the magnitude of the field due to the 1.0 μC charge is equal to the magnitude of the field due to the 4.0 μC charge, but I have tried making the equations equal to each other and don't know how to find r

 

[Incand]

If you write up the equation the distances have to satisfy how does it look?
One hint is that if you define the distance from $X$ along the line as $x$ the distance from $Y$ can be written as $(0.5-x)$ (in meters).