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)

Answer 1

z=180

Step-by-step explanation:

z=kxy

k=5

z=180

Answer 2

Answer: The value of z = 56

Step-by-step explanation:

Since we have given that

Z varies jointly with x and y i.e.

z=2 and y=2 then, z=7

So, our required equation becomes

`z=kxy`

Here, we put our first value of x, y and z ,

We get,

`7=k* 2* 2\\\\7=k* 4\\\\(7)/(4)=k`

Now, if we have x=4 and y=8 then z is given by

`z=(7)/(4)* 4* 8\\\\z=7* 8\\\\z=56`

Hence, the value of z is 56 which varies jointly with x and y.