Question

The quantity z varies jointly with x and y. If x=-1 and
y=-9, and z=-36, find z when x=2 and y=-1.

Answer 1

Answer:

8

Step-by-step explanation:

let's say xy = kz

when x = -1 and y = -9, then z = -36

so,

xy = kz

(-1)×(-9) = k×(-36)

9 = -36k

k = -1/4

when, x=2 and y=-1

(2)×(-1)=(-1/4)×z

-2=-z/4

z = 8

Answered by GAUTHMATH