Question

The variables y and x have a proportional relationship, and y = 15 when x = 3. What is the value of x when y = 4?

Answer 1

answer:

y = 19.2 when x = 8

So the answer is 8

Answer 2

Answer:

x = 5/4 = 1.25

Step-by-step explanation:

There are 4  types of relationships namely; Direct, inverse, joint and partial. This is a direct proportion.

y = 15 when x = 3

y = kx where k is the constant of proportionality.

15 = k × 3

k = 15/3

k = 5, y = 5x

the value of x when y = 4,

4 = 5x

x = 5/4 = 1.25