Select the reason that supports the following statement?

C

Step-by-step explanation:

I think the correct answer would be C since you are using lines and angles but I am not 100 percent sure. Also because A and B wouldn't make since because it is adding.

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:

step-by-step explanation: