Answer:
The answer is: yes; k = -3 and y = -3x ⇒ the 3rd answer
Step-by-step explanation:
* Lets revise how to know the relation is direct proportion
- If all the ratios of x/y are proportion (equal ratios), then they
are varies directly
* Now lets check the relation between x and y
∵ x = 1 and y = -3
∴ y/x = -3/1 = -3
∵ x = 3 and y = -9
∴ y/x = -9/3 = -3
∵ x = 5 and y = -15
∴ y/x = -15/5 = -3
∵ All ratios are equal -3 (they are proportion)
∴ y varies directly with x
* y ∝ x
∴ y = k x
∴ The constant of variation k is -3
∴ y = -3x
* The answer is: yes; k = -3 and y = -3x
