Respuesta :

apologiabiology
remember all angles in triangle add to 180

x-4+3x+100=180
4x+96=180
minus 96 both sides
4x=84
divide both sides by 4
x=21 degrees
irspow
100+(x-4)+3x=180

x-4+3x=80

4x-4=80

4x=84

x=21 degrees

(the three angles are 100,  63,  and 17 respectively)