Respuesta :

Because it is an isosceles triangle, the 2 sides that are given will be equal to each other.

15=4x+3

(subtract 3 on both sides)

12=4x

(divide by 4 on both sides)

x=3

Hope it helps!

Answer:

x = 3.

Step-by-step explanation:

1. 4x + 3 = 15

2. Subtract 3 from both sides.

3. Divide by 4 from both sides.