Question

If z varies jointly with x and y when x=3, y=-1, and z=12, what is z when x=-5 and y=6

Answer 1

Explanation:

z = 12 = k × 3 × -1

12 = k×-3

-4 = k

z = k× -5×6 = k×-30 = -4 × -30 = 120