First, you should see that the bottom right corner is an angle on the other side. So subtract 180 from 95 to get 85. Since all angles in a triangle add up to 180, You do 85 + 60 + x = 180. You simplify further to get 145 + x = 180.
Subtracting 145 from both sides leaves you with x = 35, which gives you C.
Another way you can solve this is by simply subtracting the lengths from each other giving you a value of 35 for your x value but of course using this method will not always be the case
The answer is D, because the others can be solved. A when factored is equal to -3, when B is factored it is equal to 3,-1, when C is factored it is 1,-4. D can be solved but you will only get irrational numbers which can't be used.
