Question

Two tiny objects with equal charges of 71.0 µC are placed at two corners of a square with sides of 0.340 m, as shown. How far above and to the left of the corner of the square labeled A would you place a third small object with the same charge so that the electric field is zero at A?
Picture looks like whats provided below:
Please, i need steps :))

A
l
l
0-----0