Question

Find an equation of variation in which y varies inversely as x and y=5 and x=21. Then find the value of y when x=10.

Answer 1

see explanation

Explanation:

Given that y varies inversely as x then the equation relating them is

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

To find k use the condition y = 5 , x = 21

k = yx = 5 × 21 = 105

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

When x = 10, then

y =
`(105)/(10)` = 10.5