Answer:

Step-by-step explanation:
Since each side of a line is 180 degrees, we can write the following system of equations:

Add both equations to solve for
:

Now substitute
into
to solve for
:

Finish by substituting both variables to solve for
:

Answer:
A: the same line
Step-by-step explanation:
Answer:
x = 7
Step-by-step explanation:
=> 9/72 = 3x-20/56
=> 9×45/72 = 3x-20
=> 27/3 = x
=> x = 7