Answer:
x = 8
Step-by-step explanation:
Every angle in an EQUILATERAL triangle = 60°
so 9x -12 = 60
9x = 72
[tex]9x - 12 = \frac{180}{3} = 60 \\ [/tex]
[tex]9x = 60 + 12[/tex]
[tex]9x = 72[/tex]
[tex]x = \frac{72}{9} \\ [/tex]
[tex]x = 8[/tex]
hence the value of x is 8...
