Final answer:
To solve for x using the triangle sum theorem, the expressions representing the angles of the triangle were combined and set equal to 180 degrees, following which basic algebraic steps were used to find that x is approximately 37.333.
Step-by-step explanation:
The student's question requires solving for x using the triangle sum theorem, which states that the sum of the angles inside a triangle always equals 180 degrees. Given the three expressions for the interior angles - 2x - 10, x + 18, and 60 - we can set up an equation:
2x - 10 + x + 18 + 60 = 180
Combine like terms:
3x + 68 = 180
Subtract 68 from both sides:
3x = 112
Divide both sides by 3:
x = 37.333...
Therefore, x is approximately 37.333.