Posted by Caitlyn on Thursday, December 2, 2010 at 7:35pm.
A direct variation is such that the ratio of y/x is always constant (but x≠0).
For example, the line
L: y=2x is a direct variation.
Points on the line could be (1,2),(2,4),(5,10), noting that the ratio x/y is always 1/2. Consequently, the line passes through origin.
The general equation of a direct variation is y=mx.
Given an ordered pair where x≠0 and y≠0, we can find m by substituting x and y into the general equation.
For example, for the point (2,10), we put 10=m(2), solving gives m=10/2=5.
The equation of the direct variation is therefore:
y=5x
I will leave the rest to you as an exercise.
(x,8) and (6,-16) can you give me the answer that's all I need thanks