Verified Answer :

caylus

Hello,

n=kz(x+y)²
with n=18,x=2,y=1 and z=3
==>18=k3(2+1)²
==>k=18/27=2/3


Answer:

Constant of variation is, \(\frac{2}{3}\)

Step-by-step explanation:

Joint Variation states that it is jointly proportional to a set of variables i.e, it means that z is directly proportional to each variable taken one at a time.

Given the statement: The quantity n varies jointly with the product of z and the square of the sum of x and y.

"The square of sum of x and y" means \((x+y)^2\)

"Product of z and the square of the sum of  x and z" means \(z \times (x+y)^2\)

then; by definition we have;

\(n \propto z \times (x+y)^2\)

our equation will be of the form of:

\(n = k \cdot z(x+y)^2\)   ......[1] ; where k is constant of Variation.

Given: n =18 , x =2 , y= 1 and z = 3

Solve for k;

Substitute these given values in [1] we have;

\(18= k \cdot 3(2+1)^2\)

Simplify:

\(18= k \cdot 27\)

Divide both sides by 27 we get;

\(k = \frac{18}{27} = \frac{2}{3}\)

therefore, the constant of variation is, \(\frac{2}{3}\)