Write the equation of direct variation for x = -3, y = 4.

Question

anonymous · Answer

How do u do this plz help

anonymous · Answer

In order to write a variation equation, we have to know how it varies, which your problem will specify. Does your problem let us know that y varies directly with x?

anonymous · Answer

yes

anonymous · Answer

It varies

anonymous · Answer

If so, the variation equation of y varying directly with x is y=kx
$$y=kx$$
$$4=k(-3)$$
$$4=-3k$$
$$k =-\frac{ 4 }{ 3 }$$

Variation equation is
$$y=-\frac{ 4 }{ 3 }x$$

anonymous · Answer

thx man your a big help

anonymous · Answer

No proble, but remember that "it varies" is irrelevent. You need to know if it varies directly, inversely, jointly, etc.

anonymous · Answer

that's where you know how to get the formula. 
y varying directly with x is y=kx
y varying inversely with x is y=k/x