Question

z varies directly with x and inversely with y. When x=4 and y=10, z=2. Find z when x= 5 and y=3.

Answer 1

this means zy/x = constant

Answer 2

hence zy/x , when z is 2, y=10 and x=4 is (2)(10)/4 = 5

now put zy/x = 5 at x=5, y=3 and find z

Answer 3

understand?

Answer 4

??

Answer 5

hold on im trying to understand :b

Answer 6

i dont get the second part

Answer 7

which one?

Answer 8

now put zy/x = 5 at x=5, y=3 and find z <---- this

Answer 9

see...we know that the expression zy/x is always equal to 5 dont we?

Answer 10

yes

Answer 11

soo... what do we do

Answer 12

so zy/x = 5

means z(3)/5 =5

(plugging in x and y)
now find z

Answer 13

ohh okay. thank you

Answer 14

not a problem :)

Answer 15

lets suppose z=kx and z=u/y, k and u are constants ... when z=2,x=4,y=10
we get z=0.5x and z=20/y
now just put the x=5 and y =3
u will get z=5/2 and z=20/3

Answer 16

i dont think im getting the right answer :'(

Answer 17

nvm igot it!

Answer 18

ohh great if u got it

Answer 19

thank you

Answer 20

for helping me

Answer 21

wait soo i ended up with... z= 5 2/5 times 5 over 3 butt now idk how to do that on the calculator cause i know im doing it wrong...

Answer 22

hmm i ddnt get what u asking can u plz explain lil more?