Solve for X in the Linear Equation x + 2x = 9

To solve this problem, we'll follow these steps:

• Combine like terms on the left side of the equation.
• Solve for $x$ by isolating it on one side of the equation.

Let's work through the solution:

Step 1: Combine like terms in the equation $x + 2x = 9$. The terms $x$ and $2x$ are like terms because they both contain the variable $x$. When combined, these terms give us:

$x + 2x = 3x$

Step 2: The equation now simplifies to:

$3x = 9$

Step 3: Solve for $x$ by dividing both sides of the equation by 3 to isolate $x$:

$x = \frac{9}{3}$

The calculation gives us:

$x = 3$

Therefore, the solution to the problem is $x = 3$.