In unit-vector notation, what is the torque about the torque about the origin on a particle located

Question:

In unit-vector notation, what is the torque about the torque about the origin on a particle located at coordinate (0, -4.0m 3.0m) if that torque is due to
(a) Force F1 with components F 1x = 2.0 N, F1y = 0, and
(b) Force F2 with components F 2x = 0, F2y = 2.0 N, F2 = 4.0N?