If y ∝ and y = 4 when x = 2.5, find : (a) y when x = 20

(b) x when y = 5

Step-by-step explanation:

Y = k1/x

4 = k 1/2.5

2.5 x 4 = k

10 = k

Now using this equation we will find the other answers

A) find y when x = 20

Y = k 1/x

Putting values

= 10(1/20) = 1/2 = 0.5

B) find x when y = 5

Y = k 1/x

Putting values

5 = 10 1/x

5x = 10

x = 10/5 = 2

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)