Hello
To solve this question, we can easily equate both sides.
[tex]\begin{gathered} 28\text{mi}=4hr \\ \text{xmi}=7hr \end{gathered}[/tex]Cross multiply both sides and solve for x.
[tex]\begin{gathered} 4\times x=28\times7 \\ 4x=196 \\ \text{divide both sides by the coefficient of x} \\ \frac{4x}{4}=\frac{196}{4} \\ x=49 \end{gathered}[/tex]From the calculations above, she will cover 49 miles in 7 hours.
