Answer:
4
km
Explanation:
To find how much farther Hallie biked after lunch compared to the amount she biked before lunch, we can subtract the amounts:
6
![(1)/(4)-1(5)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/y8ipjp8d46n2tlzvvnj32zl5f077rm4ydy.png)
However, we can only subtract fractions that have the same denominator, so we need to convert
to a fraction with a denominator of 8:
![(1)/(4)=(2)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h4qmosj5v5xafibx90p52amxztmkksixer.png)
Now, we can't subtract 2 from 8, so we need to 'borrow' from the 6 to make the fraction larger:
![6(2)/(8)=5(10)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5amoifrs8dmcobf9x5sffs1werifsttllp.png)
Now subtract:
![5(10)/(8)-1(5)/(8)=4(5)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gqekvh730qrhmdjkkqdh5jpkrh8gtsnmer.png)