Acrate is pulled to the right with a force of 83.6 n, to the left with a force of 121.7 n, upward with a force of 633.6 n, and downward with a force of 241.7 n. what is the net external force in the x direction?

We can assume here that left and right directions are -X and + X directions respectively

Similarly its perpendicular directions are +Y and -Y i.e. upwards and downwards respectively

So here it is given that

+X direction

- X direction

+ Y direction

- Y direction

Now net force in X direction is required here in this question

So here in X direction there are two forces opposite to each other

so in order to find net force we need to add them vector addition rule

so here

so it requires 38.1 N force towards left

at right angles to each other