Is 3y=9x a direct variation and if so, what is the constant?

2 Answers
Apr 13, 2018

k=3

Explanation:

a direct variation equation has the form

xy=kxk is the constant of variation

3y=9xdivide both sides by 3

y=3x

this is a direct variation equation with k=3

Apr 13, 2018

Yes, it is. And constant is 3. See below

Explanation:

3y=9x is a direct variation because for two diferente values values of x, lets say x0 and x1 we have

3y0=9x0 and 3y1=9x1 substracting both we have

3y03y1=9x09x1

3(y0y1)=9(x0x1) from here we have

y0y1x0x1=93=3