Question

(BEST ANSWER GETS MEDAL!) A man started walking at 3 mph towards a city 72 miles away. Later, he was picked up by a motorist who took him to the city at 42 mph. If the entire trip took 4.5 hours, how far did the man walk? (JUST SHOW THE EQUATION YOU WOULD USE, NOT THE ANSWER)

Answer 1

we can do this
did you try it with numbers?

Answer 2

no, I just need the equation for solving it

Answer 3

Sorry, i just think it would be better for me to try to solve it myself :)

Answer 4

lol that is the hard part, finding an equation
once you have it solving is routine
all the work comes in finding the equation
i would start out with two variables, say x is the distance walked and y is the distance in the car, then you know \(x+y=72\) and you can also get an equation involving time, as it is distance divided by rate
i can show you if you like or let you work on your own

Answer 5

Can you show me? I'm suddenly quite confused xD @satellite73

Answer 6

ok sure

Answer 7

Yay thank you!

Answer 8

we know the total is 72 right? so if we call the distance walked \(x\), which is what we have to solve for, we can either write \(x+y=72\) or we can just say the distance in the car is \(72-x\) either way

Answer 9

Yes, that makes sense

Answer 10

good
now we have to deal with the time business
we know time is distance divided by rate
so the time walking is \(\frac{x}{3}\) and the time in the car is \(\frac{72-x}{42}\)

Answer 11

yeah

Answer 12

and to total time is \(4.5\) so
\[\frac{x}{3}+\frac{72-x}{42}=4.5\] and we can solve for \(x\)

Answer 13

Ooh that makes sense xD can I try to solve this and you tell me if I made any mistakes?

Answer 14

ok

Answer 15

i give you a hint
if you get a whole number, it is right

Answer 16

I got x = 9, is that correct?

Answer 17

@satellite73 also, I'm unsure of the way I solved it, how could show what you would do? :)

Answer 18

yes it is 9

Answer 19

Wait never mind, I understand how to do it!

Answer 20

:)

Answer 21

so whatever you did, it is right
me, i would multiply both sides by \(42\) as step one to clear the fractions

Answer 22

yep that's what I did! Thank you so much for your help!!!!

Answer 23

yw !