Question

Which is an equation of a direct proportion?

a.y=1/6x+6 b.y=6/x
c.y=6x-6 d.y=6x

Answer 1

Option D. y=6x

Explanation:

we know that

A relationship between two variables, x, and y, represent a direct variation if it can be expressed in the form
`y/x=k` or
`y=kx`

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin

Verify each case

case a) y=(1/6)x+6

Is a linear equation, but is not a direct variation. The line not passes through the origin

case b) y=6/x

The equation represent an inverse variation

case c) y=6x-6

Is a linear equation, but is not a direct variation. The line not passes through the origin

case d) y=6x

The equation represent a direct variation