Question

Find the constant of variation k for the direct variation ​

Answer 1

The constant of variation is k = -2 ⇒ (B)

Explanation:

The equation of the direct variation is y = k x, where

• k is the constant of variation

• The constant of variation k =
  `(y)/(x)`

The given table has 4 points (-1, 2), (0, 0), (2, -4), (5, -10)

We can use one of the points [except point (0, 0)] to find the value of k

∵ (-1, 2) is a given point

∴ x = -1 and y = 2

∵ k =
`(y)/(x)`

→ Substitute the values of x and y in the relation above

∴ k =
`(2)/(-1)`

∴ k = -2

The constant of variation is k = -2