Question

Look at the following table. Is this relation direct variation? if so, find the constant of the variation and write the function rule (y=kx).

Answer 1

If two variables, x and y have a direct variation, the formula for the relationship is

y = kx

where

k is the constant of proportionality

k = y/x

Looking at the table,

k = - 21/3 = - 14/2 = - 7/1 = - 7

Thus, k = - 7

Thus, the rule is

y = - 7x

It is a direct variation