How to approach a dynamics problem I haven't been taught properly

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Hello there,

I am working on a dynamics question, but I am not sure how to tackle it since my teacher has not really taught this topic well.

I would like some advice on how to start the question off and the method that I can use to solve, I don't need you to do all the work for me. My course exam is coming up soon, so its important that I learn how to tackle these kinds of questions alone.

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Since nothing is said about velocity, assume it wants the minimum work necessary, i.e. you can assume that it is done so slowly that you can ignore KE. That also means you can ignore accelerations.
If there were no friction you could just use work conservation (potential energy change), but since there is friction you have to deal with the forces.
So take the box as sliding at a slow steady speed. What forces act on the box? What force balance equations can you write?
 
The work done will be the [net forces on the block (in the direction of motion)] multiplied by the distance moved. What forces are acting on the block. Can you break down the forces into components parallel to the plane, and normal to the plane?