Item 16 The variables x and y vary directly. Use the values to find the constant of proportionality, k. Then write an equation that relates x and y. Item 16 The variables x and y vary directly. Use the values to find the constant of proportionality, k. Then write an equation that relates x and y.

k = 2

x = 2y

Step-by-step explanation:

If variables x and y vary directly, this is expressed as;

x ∝ y

x = ky

k is the proportionality constant

Let's assume the value of x and y since we are not given;

x = 20

y = 10

Substitute

20 = k(10)

10k = 20

k = 20/10

k = 2

Hence the constant of proportionality is 2

Substitute i=k = 2 into the equation x = ky

x = 2y

Hence an equation that relates x and y is x = 2y

Note that the values here are assumed value, you can use the same method for any values of x and y

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.