Asked by Sam


Suppose y varies jointly with x and z, and x = 4 when y = 8 and z = -2.What is the value of x when y = 12 and z = 3?

A. -4

B. 4

C. 15

D. 9
Answered by Chol

y = kxz

8 = k(-2)(4)
8 = -8k
k = -1
y = -3x
12 = -3x
x = -4
Answer is A