Respuesta :

All angles in a triangle add up to 180

180 = 9 + 15 + 2x - 1 + 3x

180 = 24 - 1 + 2x + 3x

180 = 23 + 5x

180 - 23 = 5x

157 = 5x

Divide both sides by 5

X = 31.4 or 157/5