Question

Which relation is a direct variation that contains the ordered pair (2,7)?

Answer 1

D.
`y=(7)/(2)x`

Explanation:

We are asked to find the equation, which represents the direct variation that contains the ordered pair (2,7).

When two quantities are proportional to each other, they are in form
`y=kx`, where, k represents constant of variation.

Upon substituting
`y=7` and
`x=2` in above equation, we will get:

`7=k\cdot 2`

Let us solve for k by dividing both sides by 2:

`(7)/(2)=(k\cdot 2)/(2)`

`(7)/(2)=k`

Therefore, our required equation would be
`y=(7)/(2)x` and option D is the correct choice.