Question

The variable y varies jointly with x and w when y = - 42, x = 2, and w = -3.

1.) Find the constant of variation.
k=

Answer 1

k = 7

Explanation:

given y varies jointly with x and w then the equation relating them is

y = kxw ← k is the constant of variation

to find k use the condition when y = - 42, x = 2 and w = - 3 , then

- 42 = k × 2 × - 3

- 42 = - 6k ( divide both sides by - 6 )

7 = k

constant of variation is k = 7