A regular pentagon and an equilateral triangle have the same perimeter. The perimeter of the pentagon is 5(x-2) inches. The perimeter of the triangle is 4(1/2x+2) inches. What is the perimeter of each figure?

so, set them equal

5(x-2) = 4(1/2 x + 2)
5x-10 = 2x + 8
3x = 18
x=6
Now use that to find the perimeters