Question

Determine whether y varies directly with x. If so, find the constant of variation k.

x: y:
4 6.4
7 11.2
10 16
13 20.8

Answer 1

I forgot how to do this. x1 y2 or something?

Answer 2

When y varies directly with x the equation is y=kx. So you would plug in the x values in place of x and the y in place of y, then you solve for k by dividing both sides by the x value. In this case each time you divide you get 1.6 directly.

Answer 3

*so it varies directly.

Answer 4

So, 6.4 = (k)4?

Answer 5

yes. and
11.2=7(k)
16=10(k)
20.8=13k

Answer 6

I see. Thanks.

1.6 is the constant and I just have to do each set.

Answer 7

yeah, sorry if that came across unclear.