I NEED HELP, I NEED TO SHOW WORK

X=18
y=20

why?
just add 6 to each value to get the missing number. you get 6 by subtracting 15-9 since 9 isn’t a missing number in the first triangle.

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .