3. If y varies inversely as x and y = 20 when x=9, find y when x=18.
A. 11 B. 10
C. 12
D.13​


Sagot :

Answer:

B. 10

Step-by-step explanation:

In order to find y when x is 18, we have to find the value of constant 'k' first.

y = k/x

k = xy

k = 20(9)

k = 180

Now that we know 'k', let's substitute its value in the formula to get y.

y = k/x

y = 180/18

y = 10