We have a system of equations to solve:

1. $y = 12$
2. $4x - y = 8$

Step 1: Substitute $y = 12$ into the second equation.

Substitute $y$ into $4x - y = 8$: $4x - 12 = 8$

Step 2: Solve for $x$.

Add 12 to both sides: $4x = 20$

Divide by 4: $x = 5$

Final Answer:

$x = 5, \quad y = 12$

Would you like more details about this process or additional examples?

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Here are 5 related questions to explore:

1. How do you solve systems of equations with substitution?
2. Can you solve the same system using the elimination method?
3. How would you solve the system if $y = 12$ were instead $y = 4x$?
4. What happens if the equations are parallel or identical?
5. How do you graphically represent this solution?

Tip: Always substitute values back into the original equations to double-check your solutions!