We know that with a straight line, the resulting angle is 180.
So, knowing this:
6x+12+5x+3=180
Solve for x
11x+15=180
11x=165
x=15
Plug x back into your respective angles
Angle 1: 6(15)+12=102 degrees
Angle 2: 5(15)+3=78 degrees
Therefore angle 2 is 78 degrees.
