Question

Find the value of unknown if X and Y vary inversely.

Answer 1

x = 60, y = 12

Explanation:

Given that x and y vary inversely then the equation relating them is

y =
`(k)/(x)` ← k is the constant of variation

To find k use the ordered pair (180, 3 ) , then

3 =
`(k)/(180)` ( multiply both sides by 180 )

540 = k

y =
`(540)/(x)` ← equation of variation

When y = 9, then

9 =
`(540)/(x)` ( multiply both sides by x )

9x = 540 ( divide both sides by 9 )

x = 60

When x = 45, then

y =
`(540)/(45)` = 12