Set it up 180=(7x+10)+ z because angle b is on the flat line and then solve for x (180-10, then 170/7) and you’ll get the value of x and from there you can put it in all
It's the first choice. If you multiply the first equation by 3, your y term is a +12, and if you multiply the second equation by 4, your y term is a -12. When you add them the y terms cancel each other out.
What are you supposed to solve
What is the question you are trying to ask?
