To solve the linear system given in the image:

y = 2x + 5 \tag{1} 3x - y = -4 \tag{2}

We can use substitution since equation (1) already expresses $y$ in terms of $x$. Here's the step-by-step solution:

1. Substitute $y = 2x + 5$ from equation (1) into equation (2): $3x - (2x + 5) = -4$

2. Distribute the negative sign: $3x - 2x - 5 = -4$

3. Simplify the equation: $x - 5 = -4$

4. Solve for $x$: $x = -4 + 5 = 1$

Thus, the $x$-value of the solution is $\boxed{1}$.

Let me know if you'd like further details or have any questions. Here are some related questions:

1. How do you solve a system of equations using the substitution method?
2. What is the elimination method for solving systems of equations?
3. How can you verify the solution to a system of linear equations?
4. What are the advantages of substitution over other methods in certain cases?
5. Can all systems of linear equations be solved using substitution?

Tip: Always check your solution by substituting the values back into the original equations!