Hey there...
The correct answer is (C) 105° and here's how I got it.
-3+18x+13+=180° (they are corresponding angles and sum upto 180°)
next step is collecting the like terms so we have 18x+13x-3-3=180°. which is the same thing as 18x+13x-6=180° so you add 6 to both sides and we'll have 18x+13x=186 so we solve for x by adding 18x to 13x which gives 31x then we divide so we have 31x/31=186/31 and x=6.
Plug in the values of x and the equation will give -3+18(6)= 105° and the angle happens to be a vertical angle so B= 105°.
Hope it helps :)
