To answer this, add all of those angles. A triangle’s angles equal to 180. Then, combine like terms and solve.
5x - 40 + 3x + 2x + 20 = 180
10x - 20 = 180
10x -20 + 20 = 180 + 20
10x = 200
10x / 10 = 200 / 10
x = 20
hope that helps!! if you need any more help please comment and link ur question :)
