Answer:
x=45
Step-by-step explanation:
Okay then. In a triangle, the all three angle values combined equals to 180 degrees. So 24+30+(3x-9)=180. Then, you can solve for x.
24+30+(3x-9)=180 Equation
45+3x=180 Combine like terms
3x=135 Subtract 45 from both sides
x=45 Divide both sides by 3