If x varies jointly as y and z, and x = 8 when y = 4 and z = 9, find z when x = 16 and y = 6. 3

Joint variation says that:

if and

then the equation is in the form of:

, where, k is the constant of variation.

As per the statement:

If x varies jointly as y and z

then by definition we have;

          ......[1]

Solve for k;  

when x = 8 , y=4 and z=9

then

Substitute these in [1] we have;

⇒

Divide both sides by 36 we have;

Simplify:

⇒

to find z when x = 16 and y = 6

Substitute these value we have;

⇒

Multiply both sides by 9 we have;

Divide both sides by 12 we have;

12 = z

or

z = 12

Therefore, the value of z is, 12

step-by-step explanation:

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation: