Question

Y varies inversely as x. If x= -5 then y =10. Find y when x=4

Answer 1

y = - 12.5

Explanation:

Given 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 x = - 5 when y = 10, then

k = yx = 10 × - 5 = - 50

y =
`(-50)/(x)` ← equation of variation

When x = 4, then

y =
`(-50)/(4)` = - 12.5