Question

6. Find the constant of variation k for the direct variation.

4x = -y
K = -1
K=-1/4
K=4
K=-4

Answer 1

Given:

The equation for the direct variation is

`4x=-y`

To find:

The constant of variation k for the direct variation.

Solution:

If y is directly proportional to x, then

`y\propto x`

`y=kx` ...(i)

Where, k is constant of variation or constant of proportionality.

We have,

`4x=-y`

It can be written as

`-y=4x`

Multiply both sides by -1.

`y=-4x` ...(ii)

On comparing (i) and (ii),we get

`k=-4`

Therefore, the correct option is D.