Z varies inversely with the product of x and y. When x = 2 and y = 4, z = 0.5

What is the value of z when x = 4 and y = 9?

Hello,

z=k / (xy), if x=2 and y=4 then z=1/2

==>1/2=k / (2*4) = = >k=8*2==>k=4

We represent this indirect variation by,

z = k/xy

where k is the constant of the variation.

Substituting the first set of values for the variables,

0.5 = k / (2 x 4); k = 4

Now for the second set,

z = 4 / (4 x 9); z = 1/9

Thus, the value of z is 1/9.