Answer :
hello
whenever she hikes, she drinks half bottle for 1/2 mile. But yesterday, she hiked 1 mile.
let the number of miles she hiked be represented by y
number of bottles she drank be represented by x
[tex]\begin{gathered} \frac{1}{2}=1\text{mi} \\ x=\frac{3}{4} \\ \text{cross multiply} \\ \frac{3}{4}\times\frac{1}{2}=x\times1 \\ x=\frac{3}{8} \end{gathered}[/tex]from the calculation above, she drank 3/8 of a bottle
[tex]y=\frac{1}{2}x[/tex]the above is the general expression
so for every mile she hiked, we can easily calculate the quantity of water she drank