Question

z varies jointly with x and y. If x = 2, y = 3, and z = 4, write the variation equation and find z when x = −6 and y = 2.

Answer 1

Explanation:

that means

z = k×x×y

4 = k×2×3 = k×6

k = 4/6 = 2/3

so, when x = -6 and y = 2, we get

z = 2/3 × -6 × 2 = 2 × -2 × 2 = -8