(1.5, 7.5) is a solution of a direct variation what would be it's direct variation equation

Question

I don't understand this and I am almost failing please help me figure out how to do this I am in algebra and this is very confusing

Answer 1

Kayla,

If I'm interpreting the problem correctly, you have a direct variation relationship expressed as (x, y). In other words, x = 1.5 and y=7.5, and you are supposed to find the constant k that relates the two.

 

For direct variation, the relationship is as follows:

y = kx

Substituting y = 7.5 and x = 1.5

7.5 = k*(1.5)

Dividing both sides by 1.5, you get

7.5/1.5 = k

5 = k

Note that the starting equation will be different for a different relationship.

For inverse relationships,

y = k/x

and for joint relationships

y = kxz.

Hope this helps!