The perimeter of an equilateral triangle is 15 x + 30 units. Which expression can be used to show the side length of one side of the equilateral triangle? 15 (x + 2): Each side length is x + 2 units. 30 (one-half x + 1): Each side length is One-half x + 1 units. 5 (3 x + 6): Each side length is 3 x + 10 units. 3 (5 x + 10): Each side length is 5 x + 10 units.

Step-by-step explanation:

An equilateral triangle is a triangle that has all of its sides equal. Let a, b and c be the sides of the equilateral triangle. Since all the sides are equal, then

a = b = c.

The perimeter of the triangle is the sum of all the sides of the triangle.

P  = a + b+ c

GIVEN THE PERIMETER OF THE EQUILATERAL TRIANGLE AS P = 15 x + 30 units and a = b = c, then;

15 x + 30 = a + b + c

15 x + 30 = a + a + a (since all sides are equal)

15 x + 30 = 3a

3a = 15 x + 30

3a = 3(5x+10)

Dividing both sides by 3 will give;

3a/3 =   3(5x+10)/3

a = 5x+10

Hence, the length of one side of the equilateral triangle is 5x + 10 units.