Question

Can someone explain to me how to do this?

determine whether y varies directly with x. if so, find the constant of variation k and write the equation.

x y
5 20
15 60
45 180
135 540

Answer 1

y = kx is direct variation where k is a constant

Answer 2

k >= 1


as x increases y will also increase

Answer 3

is this the case with your table?

Answer 4

yeah!

Answer 5

right now can you see what k is?

Answer 6

5 * k = 20
15 * k = 60

do you see the pattern?

Answer 7

yeah

Answer 8

k = 20/5 = 4

equation is
y = 4x

Answer 9

thanks!!