Answer:
-5
Step-by-step explanation:
2x+3=-7
2x=-7-3
2x=-10
x=-10/2
x=-5
Answer:
The third side is around 58.043
Step-by-step explanation:
Use the law of cosines: 
Plug in the two sides we know (into a and b) and the angle we know (into angle C).
Thus:
Use a calculator:


(Note: Make sure you're in Degrees mode.)
Answer:

Step-by-step explanation:
Put x = 3, y = 2 and z = 5 to the given expression
:

Here, as the sides are equal, middle line would be exact half then the longer (bottom) side of the triangle.
48 = 2(3x)
6x = 48
x = 48/6
x = 8
In short, Your Answer would be Option D
Hope this helps!