In order to be fulfilled m // n we must take into account the following angle:
180-105 = 75 degrees
Therefore, we match this angle to the given expression.
We have then:
3x-18 = 75
Clearing x we have:
3x = 75 + 18
x = 93/3
x = 31 degrees
Answer:
the value of x is:
A.
31
