I think something u have skipped in the question

 if u r asking for the force F required to move the block then d first step is to resolve mg in its two component & then make balance condition R=mgcosθ    & F= mgsinθ + f            f=uR

 F= mg sinθ + µR =mg sinθ+ µmg cosθ =mg( sinθ+cosθ)  as d body is moving up therefore friction f will act opposite to applied force in the direction of mgsinθ thus sign in b/w should be + , whereas u have used -ve 

 if u asking to move the body  up then the solution submitted will be correct, But if u are asking for just to make it move or to move downward then the sign vyl be changed then balance conditn will be

 F = mgsinθ-f = mg (sin θ -ucosθ)     here f=uR & r=mgcosθ   as force to move it is along sin component thus sign will be same 7 as friction f is acting opposite thus it has -ve sign . thus both ans are applicable depending upon the force is req in which direction