Final answer:
To solve the equation 2x + 129 = 380, subtract 129 from both sides to get 2x = 251, then divide both sides by 2 to get the solution, x = 125.5.
Step-by-step explanation:
To solve the equation 2x + 129 = 380, we need to isolate the variable x on one side of the equation. First, we subtract 129 from both sides, which gives us 2x = 380 - 129. Simplifying this, we get 2x = 251. Next, we divide both sides by 2 to find the value of x, which results in x = 251 / 2. Therefore, the solution is x = 125.5.