How to find the positon of a local vector

[Aceix]

Homework Statement

Determine the resultant force R that is equvalent to the forces exerted by the tugboats on the barge. Specify the coordinates of the point on the x-axis through which R passes.
Pls check attached file!

Homework Equations

Moment=Force x perpendicular distance

The Attempt at a Solution

Findin the R resulted to 15.7i + 11j
Total moment about A gives 8tons.m clockwise.
Then using this force-couple system, the resultant force should be placed such that it yields the same moment.
Letting x be the distance between Ry(y component so I get a perpendicular relationship) and pt. A, and equating the moment(that of R and the 8tons.m) reveals that x=0.7m. Then the coord is 60m-.7m=59.3m.

 

[haruspex]

Total moment about A gives 8tons.m clockwise.

You forgot something.

 

[Aceix]

You forgot something.

Dont see anything. What did I miss?

 

[haruspex]

Dont see anything. What did I miss?

The force is 8 tons. What is the moment from the force about A?

 

[Aceix]

The force is 8 tons. What is the moment from the force about A?

Oh..60x8tons.m

 

[Aceix]

So...55.6m?

 

[haruspex]

So...55.6m?

As x coordinate? Seems much too large. Please post your revised working.