Question

Determine whether y varies directly with x. If so,

find the constant of variation k and write the
equation
x y
7 14
21 42
63 126
189 378

Answer 1

see explanation

Explanation:

If y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation and

k =
`(y)/(x)`

Check this ratio for each ordered pair, that is

k =
`(14)/(7)` =
`(42)/(21)` =
`(126)/(63)` =
`(378)/(189)` = 2

Thus k = 2 and

y = 2x ← equation of variation

Answer 2

Yes.

Explanation:

They both multiply by 3. K=3

x1=x0*3

x2=x1*3....

y1=y0*3

Y2=y1*3....