Respuesta :

migendkamilla

Answer:

21 is the value of x (you add the sides up)

Step-by-step explanation:

Answer:

1. 6x+15

2. x=5

Step-by-step explanation:

Since the triangle has sides that are the same, we know that 15 is one side and since 15/3 = 5 so x=5. Also for perimeter you add all the sides so 3x+3x+15 and add like terms so you get 6x+15.