Question

Which equation represents a direct variation? y = 2x
y = x + 4
y = 1/2x
y = 3/x

Answer 1

Equation y =2x represent the direct variation .

Explanation:

Given : Equations y = 2x , y = x + 4 , y = 1/2x , y = 3/x .

To find : Which equation represents a direct variation.

Solution : We have given that equations

Direct variation : The statement "y varies directly as x," mean y and x always have the same ratio: k =
`(y)/(x)`.

Where k is constant of variation ,

We can write it as y = kx .

We can see that in equation y = 2x is the same as the above equation

On comparing k = 2.

Therefore, Equation y =2x represent the direct variation .

Answer 2

The statement " a direct variation "
means that when x increases,y increases
We say that y varies directly with x if Y=kX k called the constant of variationthe answer is
y = 2x
k=2