ΔRST was , then dilated, to create ΔZXY.

Hello! Remember you have to write complete questions in order to get good and exact answers. Here I'll assume translation in order to explain some concepts.

Suppose you have the following triangles:

So ΔRST was first translated and the dilated by the following rules:

So as you can see:

Conclusion:

ΔRST was translated, then dilated, to create ΔZXY.

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:

whats the