## anonymous one year ago The variable Z is inversely proportional to X. When X is 3, Z has the value 2. What is the value of Z when X = 13

1. anonymous

@Nnesha can you help?

2. Nnesha

do you know the definition of inverse proportion ?

3. Nnesha

i mean formula*

4. anonymous

i know to do it , its just the decimals get me confused. 2/3 is what? then whatver that is i just multiply it by 13

5. insa

As z is inversely proportional to x. Then z=k/x substitute the values of z and k and find the value of k

6. Nnesha

you don't have to divide Z = k/ z substitute z and k values and x is dividing by k so you need to do opposite of division

7. insa

After finding the value of k, let z=k/x. Then substitute the value of k u found and the other value of k, solve it further and you'll get the answer :)

8. anonymous

9. Nnesha

k equal to what ?

10. Nnesha

k is constant of variation first you need to solve for k $\huge\rm \color{reD}{z}=\frac{ k }{ \color{blue}{x} }$ $\color{ReD}{z =2}~~~~\color{blue}{x=3}$

11. anonymous

so then itll be 2=26?

12. anonymous

or is it 6?

13. Nnesha

yes k=6 now use the same formula substitute k and z values solve for z

14. anonymous

so then its 2=2

15. Nnesha

how ?

16. anonymous

2=6/3 ?

17. Nnesha

no you need to find z when x =13 this is 2nd part so substitute 13 for x

18. anonymous

so 2=6/13?

19. Nnesha

no u need to find z so it should be z =6/13

20. anonymous

0.461?

21. Nnesha

yeah or leave it as fraction form

22. Nnesha

.4615 ^round it

23. anonymous

0.462

24. Nnesha

lO_Oks right

25. anonymous

i need one more The variable Z is directly proportional to X, and inversely proportional to Y. When X is 6 and Y is 3, Z has the value 6. What is the value of Z when X = 10, and Y = 8

26. Nnesha

directly proportional = y =kx multiply k with x inverse = y = k/x divide k by x so translate that into the equation

27. Nnesha

is means equal sign so z =

28. anonymous

so multiply 6x6 and 6x3

29. Nnesha

6 times 6 ? there is only one 6

30. Nnesha

The variable Z is directly proportional to X z= kx and 2nd part is inversely proportional to Y so z =kx/y

31. Nnesha

substitute x,y and z values solve for k

32. anonymous

so what do i do first?

33. Nnesha

substitute x ,y and z values solve for k

34. anonymous

im so confused

35. Nnesha

why ? what you didn't understand :=)

36. anonymous

i substitued and got 10 and 16

37. Nnesha

so how did you get 10 please show your work so i can figure t out ur mistake :=)

38. anonymous

oh wait no , i got 60 and 24

39. Nnesha

work ?

40. Nnesha

k= ?

41. anonymous

all i did was multiply 10 by 6 and 8 by 3

42. Nnesha

When X is 6 and Y is 3, Z has the value 6. this is first part you need to find k value first ALWAYS!

43. Nnesha

substitute x for 6 y for 3 z for 6 solve for k