Question

Suppose y varies jointly as x and z. If y=15 when x=1/2 and z=6, what is the constant of variation?

Answer 1

k = 5

Explanation:

Given y varies jointly as x and z then the equation relating them is

y = kxz ← k is the constant of variation

To find k use the condition y = 15 when x =
`(1)/(2)` and z = 6 , then

15 = k ×
`(1)/(2)` × 6 = 3k ( divide both sides by 3 )

5 = k

Answer 2

y= 15

Explanation:

Y= Kxz

y=6 x=1/2 z=6

15= K (1/2) (6)

15= K (3)

K= 5

SO

y= (5) (1/2) (6)

Y= 15