You are given two vectors, one pointing in the x direction and the other pointing in the y direction. is it possible to find a third vector so that the sum of the three vectors is equal to zero?

Yes. The third vector should have an x component equal to the first vector pointing to the x direction and it should have a y component equal to the second vector pointing to the y direction. Having these values for the x and y components will cancel the values of the first and second vector, resulting to zero.