## Barrelracing one year ago suppose y varies directly with x. write a direct variation equation the relates x and y. then find the value of y when x =16 y=5 when x=2

1. rishavraj

For direct variation y = kx k is the propotionality constany

2. Barrelracing

@bry856

3. jim_thompson5910

y = k*x y = k*2 ... replace x with 2 5 = k*2 ... replace y with 5 solve for k to get k = _________ (fill in the blank)

4. rishavraj

After getting k ...plug the value of k and x in the equation and get y

5. Barrelracing

y=40

6. jim_thompson5910

you should have found that k = 2.5 y = 2.5x when x = 16, y = 2.5*16 = 40 so you have the correct y value

7. Barrelracing

how do I find the direct variation that related x and y?

8. jim_thompson5910

what do you mean?

9. Barrelracing

it says write a direct variation equation that relates x and y. this is still the same problem.

10. jim_thompson5910

so it just wants the equation with x and y in it

11. jim_thompson5910

the k will be replaced with the numeric value you found

12. Barrelracing

so y=40x?

13. jim_thompson5910

So you can either say $\Large y = \frac{5}{2}x$ or $\Large y = 2.5x$

14. jim_thompson5910

I started with y = kx then replaced k with 5/2 or 2.5

15. Barrelracing

ohh ok I get it now thank you

16. jim_thompson5910

np