Question

What is the value of x? x=___

Answer 1

let's notice, the interior angles are all equal, notice the angle tickmarks, so it's an equlilateral triangle, where all sides are also equal, meaning AB = AC.

$\bf 6x-3=3x+6\implies 3x=9\implies x=\cfrac{9}{3}\implies x=3$

Answer 2

since the angles are the same, the sides must be the same, so this is like solving:

6x-3 = 5x = 3x+6

Which simplifies to x=3