For the data in the table, does y vary directly with x? If it does, write an equation for the direct variation. (hint: you need to find the “k” value)

Question

anonymous · Answer

The table:
X | Y
4 | 10
10 | 25
16 | 40

anonymous · Answer

@DanJS

danjs · Answer

hi

anonymous · Answer

Hey, @DanJS can you help me out?

danjs · Answer

varies directly with x, means it is a linear equation in the form

y=k * x

danjs · Answer

put in (x,y) = one of the points and figure out k

anonymous · Answer

I don't understand where K comes from..

danjs · Answer

k is the slope, the direct variation of y as x increases

danjs · Answer

y = (5/4)x

yamyam70 · Answer

$$y = kx , k = y/x$$

danjs · Answer

5/2x i mean

danjs · Answer

y = (5/2)x

anonymous · Answer

@DanJS Isn't there more to the equation that relates to the direct variation?

danjs · Answer

not here

danjs · Answer

it is a linear relationship

yamyam70 · Answer

@Answers101 , solving for K 

From the main formula of direct variation y= kx , solving for K
K = y /x  

When you solve it and you get same results you can conclude that all of them varies directly. 

Note that direct variation means , if x will rise y will also rise and vice versa,  in this case both values of k neither changes.

anonymous · Answer

So, the answer would be Y = 5/2x that's it?

anonymous · Answer

@yamyam70

yamyam70 · Answer

Yes you are correct, that equation corresponds to the table given :)

anonymous · Answer

How do you know that the equation would be 5/2? Because the table shows X shows a decrease of 6 & Y shows a decrease of 15 so would you just simplify 15/6 to get the 5/2?

yamyam70 · Answer

5/2 is not an equation 

5/2 is the value of K in the equation y = kx

danjs · Answer

can you close this out please

anonymous · Answer

Thanks, @yamyam70

yamyam70 · Answer

@Answers101  alright goodluck :)