Respuesta :

Since the triangle is equilateral, all sides are equal. To find x, we can say that

[tex]2x+6=5x-21[/tex]

Now simplify, and isolate x.

[tex]3x=27\\[/tex]

Therefore x=9.

Substitute x for 9 in one side.

2×9+6=18+6=24.

All sides are equal to 24 and x=9.