Solve the Linear Equation: a + 7 + 3a - 15 = 0

To solve the linear equation $a + 7 + 3a - 15 = 0$, we follow these steps:

• Step 1: Combine like terms.
• Step 2: Simplify the equation.
• Step 3: Solve for $a$.

Let's execute each step:

Step 1: Combine like terms.
We have $1a + 3a = 4a$. The equation becomes:

$4a + 7 - 15 = 0$

Step 2: Simplify the equation.
Combine the constants $7$ and $-15$:

$4a - 8 = 0$

Step 3: Solve for $a$.
Add 8 to both sides to isolate the term with $a$:

$4a = 8$

Divide both sides by 4 to solve for $a$:

$a = \frac{8}{4} = 2$

Therefore, the solution to the equation is $a = 2$.