Question

Which equation represents an inverse variation function that passes through the points (4, 5) and (10, 2)?

y =
y =
y = 20x
y =

Answer 1

Answer: y = 20/x

Answer 2

An inverse variation function is of the form

`y= (k)/(x)`
where is constant.

Because the function passes through (4, 5). therefore

`5= (k)/(4) \\ or \\ k=20`
The required function is therefore

`y= (20)/(x) \\ or \\ xy = 20`

Verify that the function is correct because it should pass through the point (10, 2).
When x = 10, obtain

`y= (20)/(10)=2`
This verifies that the function is correct.

Answer:
`y= (20)/(x) \,\, or \,\, xy=20`