Question #b15bf

Feb 12, 2016

$y = 240$

Explanation:

The statement "y varies jointly as x and z" is equivalent to saying
y= kxz where the k is a constant. Varies jointly means proportional. For example, if the product of x and z doubles, so will y. To find k, just plug in the given values of y, x, and z.

$25 = k \left(2\right) \left(5\right)$
$25 = 10 k$
$k = 2.5$

Now that you know k, you can solve for an unknown y when given x and z because k doesn't change numeric value. Plug in the given x and z values.

$y = \left(2.5\right) \left(8\right) \left(12\right)$
$y = 240$