0. If 'm' and 'n' are in inverse proportion and k is a constant, then which of the lowing is correct?

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

they can both be solutions depends on the equation

step-by-step explanation:

what is the equation? ?

you need to give us more information since we can't answer