Answer:
x=-7
Step-by-step explanation:
first, subtract 4x from both sides. then you'll get:
-9=3x+12
next subtract 12 from both sides. Then you'll get:
-21=3x
then you divide each side by 3. You get:
OK this is hard math
It's an integer.
45
a line makes 180 degrees
180-135=45