Z varies jointly with x, and y, and z=7 when x= 2, y= 2

56

Step-by-step explanation:

Complete question:

Z varies jointly with x and y , x=2 and y=2, z=7. Find z when x=4 and y=8 using joint variation . (I need the problem worked out step by step)

If z varies jointly with x, and y, this is expressed as;

z = kxy

If z=7 when x= 2, y= 2

7  = k(2)(2)

7 = 4k

k = 7/4

To get z when x= 4 and y = 8

z = kxy

z =7/4 (4)(8)

z = 7*8

z = 56

Hence the value of z is 56

idk

step-by-step explanation: