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andjie
 2 years ago
Can someone explain this for me step by step? Abby rows 10 km upstream and 10 km back in a total time of 3 hr. The speed of the river is 5 km/h. Find Abby’s speed in still water. @mark_o.
andjie
 2 years ago
Can someone explain this for me step by step? Abby rows 10 km upstream and 10 km back in a total time of 3 hr. The speed of the river is 5 km/h. Find Abby’s speed in still water. @mark_o.

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mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1yeah im here now lol :D dw:1354646559750:dw

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1she row from starting point A to B then from B to A that is time from A to B + time from B to A = 3 hours

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1time Tab + T ba = 3 (1) but distance d=velocity x time,. therefore t=d/v dAB dBA  +  =3 but distances dBA=dAB=10 km v v 10 10  +  =3 v v but note that velocity of river is v=5 km/hr for upstream v= v+5 10 10 for down stream v= v5, therefore  + = 3 v+5 v5 you can algebra now ion finding v=?

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1i mean you can do the algebra now from this point ... :D

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.110/(v+5) + 10 /(v5) =3 10(v5) + 10(v+5)  =3 (v+5)(V5)

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1do multiplication and addition to simplify the numerator and the denominator..:D

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0wow i suck cause I am lost

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0the v is throwing me off

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.110 10  +  = 3 (v+5) (v5) ?  =3 (v+5) (v5)

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1for the further left, that is (v+5)(v5) = ? then mult by 10 (v+5)

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1then on the mid of it (v+5)(v5) = ? then mult by 10 (v5)

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.110(v5) + 10(v+5  = 3 (v+5)(v5)

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0ok give me a sec and let me figure this out

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1multiply the numerator then do addition on the denominator multiply them also

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1hhm where did you get 105 and 15+5 from? it should stay as 10( v5)=? and 10(v+5)=?

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0I SUBTRACTED AND ADDED 10 FROM BOTH (V5)(V+5)

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0I just want to understand it

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1I guess you didn't like my explanation

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0no i asked you a question and you left

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0I just hate math and it takes me awhile to get it together

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1Well, I just answered your question

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1I left the room to help someone else with their question, but you should not assume that I had left.

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1it should stay as 10( v5)=? and 10(v+5)=? 10( v5)= 10v 50 is it ? and 10(v+5)= 10v +50 is it ?

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1ahh you have posted this before..yeah @andjie when we start coaching you dont assume that we had left .. :D

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1@mark_o. I am convinced you are doing this the hard way.

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1and for the denominator (v+5)(V5)=?

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1haha i know..:D im sorry @Hero ...:D

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1where is that? lol... :D

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1I'll do anything to avoid a quadratic equation

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1Besides, I don't like when you get to a result where you have two solutions but have to discard one of them because it is negative.

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1i think andjie is just doing the refresher thing now.. to recall everything .. that was 7 years ago ? @ andjie?

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1http://openstudy.com/study#/updates/50bd6019e4b0de42629fcb42

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0wait I just had my high school reunion so it was 10 years ago lol

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1She's probably 28 years old

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1wow, almost 10 years ago? hmmm yeah this is a good refresher to you ... :D

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1I just posted a link to the solution

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1hhhm i cant open it, dont know why @Hero

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0I understand this better @hero hopefully I can do more like this

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1d = rt and let r = b ± w b = speed of the boat w = speed of the water current t1 = Upstream time t2 = Downsteam time 10 = 5t 2 = t1 t1 + t2 = 3 2 + t2 = 3 t2 = 3  2 t2 = 1 Upstream Formula d = rt1 d = (b  w)t1 Downsteam Formula: d = rt2 d = (b + w)t2 b  w = 5 Upstream 10 = 2(b  w) Downsteam 10 = (b + w) 10 = 2b  2w 20 = 2b +2w 30 = 4b 30/4 = b 7.5 = b 10 = b + w 10 = 7.5 + w 10  7.5 = w 2.5 = w Therefore The speed of the boat was 7.5 km/h

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1ok this is good,, directly for the solutions and answer.... ;D

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1you did really avoid the quadratic equation .. :D

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0You guys are just too smart for me

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1I usually find ways to avoid it.

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1It's a personal goal of mine

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1ok that is very good.... and andjie can copy this one to study and do for a second solution or alternate solution..........:D

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0Thank you @mark_o. you always look out for me

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1Well, back to watching Smallville. I'm trying to get to the end of the 10th season and it's taking forever.

andjie
 2 years ago
Best ResponseYou've already chosen the best response.0Have fun and thank you for your help

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1ok YW,, tc now and have fun solving..........:D

mark_o.
 2 years ago
Best ResponseYou've already chosen the best response.1thanks for doing the alternative solution, that was a good one :D @Hero...............:D

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1You're welcome. I have plenty alternative solutions up my sleeve.

Hero
 2 years ago
Best ResponseYou've already chosen the best response.1If you need an alternative solution, cite me.
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