Respuesta :

Answer:

x=9

Step-by-step explanation:

every angle of a triangle added together equals 180. ill just show my work bc its hard to explain:

7x+2 + 4x+7 + 8x = 19x+9

19x+9 = 180

     -9     -9

19x = 171    (now divide by 19)

x=9