Let \( A \) represent the area of the house. According to the problem, the area of the front yard is given as 4,200 ft².
The total area of the house plus the area of the yard is expressed as:
\[ A + 4200 \]
The problem states that this total area is 8 times the area of the house alone. Therefore, we can set up the following equation:
\[ A + 4200 = 8A \]
This equation models the real-world situation described. You can simplify it to solve for \( A \):
\[ 4200 = 8A - A \] \[ 4200 = 7A \] \[ A = \frac{4200}{7} \] \[ A = 600 \]
So, the area of the house is 600 ft². The equation that models the real-world situation is:
\[ A + 4200 = 8A \]