You can put this solution on YOUR website! Supplementary angles are angles that add up to 180 degrees. In order to solve for x, we need to set the question up as an equation. So,
x + 4x + 5 = 180
Next, combine the x and the 4x:
5x + 5 = 180
Next, we need to isolate the x. To do this, we first subtract 5 from both sides of the equation:
5x + 5 - 5 = 180 - 5