# If y varies directly as x, and y=42 as x=6, how do you find y for the x-value 3?

##### 1 Answer

Jun 3, 2015

Direct variation can be represented as:

where

so substituting :

Now, we have the value of

By cross multiplying we get

on observing the values

- when
# x = 6 , color(red)(y) = color(green)(7)xx6= 42# - when
# x = 3 , color(red)(y) = color(green)(7)xx3 = 21#