Question

a kayaker paddles upstream from camp to photograph a waterfall and returns.the kayakers speed while traveling upstream and downstream is shown below.what is the kayakers speed in still water?what is the speed of the current?????????
HELPP

Answer 1

is there supposed to be a diagram? O.o

Answer 2

yea there is but it wont let me put it

Answer 3

if u search up the question a pdf file should pop up and then u just click on it and the picture is there

Answer 4

this one?

Answer 5

yessss

Answer 6

give me a sec. i'll try to solve it on my own

Answer 7

okay thankss

Answer 8

oh, this is linear systems?!
lol, i thought this is vectors -.-

okay..
so let x be the current's speed and y be the boat's speed in still water
the current's direction is downstream

first let's do an equation for upstream
since the kayaker went upstream at a speed of 4mi/h and the kayaker's direction is opposite to the current's direction, we will have an equation of \(x-y=4\) this will be the first equation

next is the equation for downstream
kayaker's speed=7mi/h
have same direction with the current
\(x+y=7\) this will be our second equation

so we have
\(x-y=4\)
\(x+y=7\)

now use elimination or substitution to solve for x and y :)

Answer 9

oh okay tysm :))

Answer 10

did you get it? ^.^

Answer 11

how do i use substition or elimination for that ?

Answer 12

elimination is easier

you need to eliminate one variable to solve for the other one
for example you want to solve for "x"
you just add the two equations and the variable y will be eliminated

Answer 13

ohohoh so i just add 4+7=11?

Answer 14

ohhh
i get it

Answer 15

err.. not really
new equation will be : 2x=11
then just solve for x

after you solve for the value of x, substitute it in any of the two equations

Answer 16

it would be 2x=11 and then divide that which gives me 5.5

Answer 17

omg tysm

Answer 18

so thats it right

Answer 19

yes, then you need to solve for "y"

Answer 20

so i do 5.5-y=4

Answer 21

yes :)

Answer 22

?

Answer 23

oh ok omg ur so smart

Answer 24

i may need ur help for other excersices if thats okay with u

Answer 25

lol, you already get this one? O.o

Answer 26

yes i do! :) but i get confused really easily lol

Answer 27

oh ok the answer is 5.5 mi/h;1.5 mi/h

Answer 28

that's fine, you'll get used to it if you'll practice a lot

also, you may get a negative speed sometimes, which only refers to the direction of the object

Answer 29

ugh i just hate algebra
but thanks alot u saved me and oh ok :)

Answer 30

no problem :)