3. If y varies inversely as x and y = 20 when x = 4, find y when x = 8.

y=10

Step-by-step explanation:

Y varies inversely as x means y is inversely proportional to x. Therfore:

y = k/x where k is the constant of proportionality

So to find this constant we use the scenario given.

When y is 20 x is 4. So putting these values in the equation:

y=k/x

20=k/4

k=80

Now that we have K we are can find Y when x is 8:

y=80/x

y=80/8

y=10