Find the value of x for which m//n a. 31 b. 33 c. 39 d. 41

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
 
 the value of x is:
 A.
 31

D