Question

Brian rode his bike 2 mi to his friend's house. Brian's bike had a flat tire, so he had to walk home. His walking rate is 25% of his biking rate.

a. Write an expression for the amounts of time Brian spent walking and riding his bike.

b. If Brian's biking rate is 12mi/h, how much time did he spend walking and riding his bike?

Answer 1

this is adding and subtracting rational expressions

Answer 2

If b = biking rate, what is the expression for the walking rate given that his walking rate is 25% of hiss biking rate?

Answer 3

i don't know

Answer 4

"walking rate is 25% of his biking rate"
w=0.25 b

Answer 5

ok

Answer 6

how do i find the biking rate?

Answer 7

You are given the biking rate in section b. But we still need to develop the expression for the amounts of time spent walking and bike riding.

Let t_walk=time walking and t_bike=biking time. We can get the time by diving the distance by the bike or walk rate. So total time to go there and back would be\[T=t_{bike}+t_{walk}=\frac{2}{b}+\frac{2}{w}\]

Answer 8

a.\[t=\frac{2}{r}+\frac{2}{\frac{r}{4}}=\frac{10}{r} \]b.\[t=\frac{2}{12}+\frac{2}{\frac{12}{4}}=\frac{5}{6}\text{ hours} \text{ or } 50 \text{ minutes} \]