The graph of a proportional relationship contains the point (-30, 18)
what is the value of k for the relationship?
enter your answer in the box as a fraction in simplest form
k=

Step-by-step explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form or

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin

we have the point (-30,18)

so

x=-30, y=18

Find the value of k

substitute

Simplify

Divide by 6 both numerator and denominator

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)