The vertex is (7,-50)
***rewrite in standard form***
Answer:
B) 
Step-by-step explanation:
−x + 3 = 2x - 3
-2x - 2x
___________
−3x + 3 = −3
- 3 - 3
_________
−6 = −3x
__ ___
−3 −3
[Plug this back into both equations above to get the y-coordinate of 1]; 
I am joyous to assist you anytime.
-5= -5x-10
Plus 10 from both sides
5=-5x
X = -1
The total measure of all the angles in a triangle is 180°.
Since there is already a 90° angle, the other 2 angles must also add up to 90°.
The only answer that fits is x = 9.
Check:
9x7 = 63°
3x9 = 27°
Add up = 90°
:)