Question

A force,
F = (2x + 5y) N,
is applied to an object at a point whose position vector with respect to the pivot point is
r = (2x + 4y + 5z) m.
Calculate the torque created by the force about that pivot point.

Answer 1

Torque is the F x r vector cross product.

Do your x, y and z represent unit vectors?

It is conventiuonal to use i, j and k for unut vectors along x, y and z orthogonal axes.

I am confused by your notation.

Answer 2

yes x,y, z is unit vectors.