We need to determine which of the given inequalities can be used to determine how long you must walk (w) and run (r) in order to cover more than 8 miles.
We know that you can walk at a rate of 4 mi/h, and run at a rate of 6mi/h.
Thus, if you walk for w hours, you will walk a distance d₁, in miles, given by:
[tex]d_1=4w[/tex]
Also, if you run r hours, you will run a distance d₂, in miles, given by:
[tex]d_2=6r[/tex]
Now, notice that the total distance is the sum of d₁ and d₂. And the total distance, in miles, must be greater than 8.
We represent 'greater than' using the symbol '>':
[tex]\begin{gathered} d_1+d_2>8 \\ \\ 4w+6r>8 \end{gathered}[/tex]
Therefore, the correct option is:
[tex]4w+6r>8[/tex]