Please help me out with this all I need is the answer, pleaseeee

Answer:
8x-3
Step-by-step explanation:
The total perimeter is the length of all the sides of the triangle added together, in this case that is 11x+1. In order to get the length of the one side by itself subtract the other two side lengths from the perimeter. (11x+1)-(x+5)=10x-4. (10x-4)-(2x-1)=8x-3.