Answer:
B: 3x+(4x+2)=180
Explanation:
Supplementary angles are those angles that sum up to 180 degrees. The question gives you the two angles that compose the 180 degree angle thus you get the equation:
Angle 1 + Angle 2 = Supplementary Angle
In this case we see that these two angles are Angles B and C and a supplementary angle is 180 degrees thus:
(4x+2)+3x = 180
Furthermore this also allows you to find x.