Answer:
A. x=8 y=21
Step-by-step explanation:
line l and line m are parallel, and both angles that have x in the values are on the same side, so they are equal to each other.
7x+12=12x-28
+28 +28
7x+40=12x
-7x -7x
40=5x
/5 /5
8=x
Since A is the only choice that has x=8, it must be the right answer.
