Wednesday

November 25, 2015
Posted by **Caitlyn** on Thursday, December 2, 2010 at 7:35pm.

(2,10)

(8,2)

(7,21)

(2,-16)

Please Help!

- Algebra -
**MathMate**, Thursday, December 2, 2010 at 10:21pmA 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.

- Algebra -
**Sean**, Sunday, January 23, 2011 at 11:43am(x,8) and (6,-16) can you give me the answer thats all I need thanks