Question

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

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.