SOLUTION: z varies jointly as the square root of the product of x and y. If z is equal to 3 when x is equal to 3 and y is equal to 12,find x when z is equal to 6 and y is equal to 64.

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: z varies jointly as the square root of the product of x and y. If z is equal to 3 when x is equal to 3 and y is equal to 12,find x when z is equal to 6 and y is equal to 64.      Log On


   

Question 1008638: z varies jointly as the square root of the product of x and y. If z is equal to 3 when x is equal to 3 and y is equal to 12,find x when z is equal to 6 and y is equal to 64.
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
We write this is as
z+=+k%2Asqrt%28xy%29
Then we plug in to get
3+=+k%2Asqrt%283%2A12%29
3+=+6k
k+=+1%2F2
and we have
z+=+%281%2F2%29%2Asqrt%28xy%29
Then
6+=+%281%2F2%29%2Asqrt%2864x%29
6+=+4%2Asqrt%28x%29
3%2F2+=+sqrt%28x%29
and
x+=+9%2F4