Answer:
69
Step-by-step explanation:
Perimeter = sum of all sides of a regular polygon = the number of sides*length of a side
Length of a side of the given regular hexagon = 3x + 5
Perimeter of hexagon = 6(3x + 5) = 6(3x) + 6(5) = 18x + 30
Length of a side of the given regular pentagon = 4x - 1
Perimeter of pentagon = 5(4x - 1) = 5(4x) - 5(1) = 20x - 5
Since we are told that the perimeter of the regular hexagon is the same as that of the regular pentagon, therefore:
18x + 30 = 20x - 5
Solve for x.
Subtract 20x from both sides
18x + 30 - 20x = 20x - 5 - 20x
-2x + 30 = -5
Subtract 30 from both sides
-2x+ 30 - 30 = -5 - 30
-2x = -35
Divide both sides by -2
x = -35/-2
x = 17.5
Length of a side of pentagon = 4x - 1
Plug in the value of x
4(17.5) - 1 = 70 - 1 = 69
length of a side of the pentagon = 69