Respuesta :

CPED

Answer:

a) y*x = k

b) y = 3

Step-by-step explanation:

a) According to given condition:

As in inverse relation, if one quantity increases             other decreases proportionally so the equation will be:

y∝ 1/x    

Now removing proportional sign with equality a constant k is used as follows:

y = k/x

k = y*x

Putting values of y and x, we get:

k = (7) * (9)=63

b) By putting given value of x in (k=y*x)

   63 = y * (21)

   y = 63/21

   y = 3