1. **State the problem:** We have a triangle with angles 60°, (2x + 9)°, and (4x + 3)°. We need to find the value of $x$. 2. **Recall the triangle angle sum rule:** The sum of the interior angles of a triangle is always 180°. So, $$60 + (2x + 9) + (4x + 3) = 180$$ 3. **Combine like terms:** $$60 + 2x + 9 + 4x + 3 = 180$$ $$6x + 72 = 180$$ 4. **Isolate $x$:** $$6x + 72 = 180$$ $$6x = 180 - 72$$ $$6x = 108$$ 5. **Divide both sides by 6:** $$\cancel{6}x = \cancel{6}18$$ $$x = 18$$ 6. **Final answer:** The value of $x$ is $18$ degrees.