Question

If y ∝ 1∕x and y = –2 when x = 14, find the equation that connects x and y.

A) y = –28x
B) y = –7x
C) y = –28∕x
D) y = –7∕x

Answer 1

Answer:

C

Step-by-step explanation:

Given y ∝ $\frac{1}{x}$ then the equation relating them is

y = $\frac{k}{x}$ ← k is the constant of variation

To find k use the condition y = - 2 when x = 14 , then

- 2 = $\frac{k}{14}$ ( multiply both sides by 14 )

- 28 = k

y = - $\frac{28}{x}$ ← equation of variation