Respuesta :

AwkwardBlueDarling
All the angles in a triangle equal 180 degrees so 128 + (5x+10) + 9x = 180

Group the like values to get 138 + 14x = 180

Subtract 138 from 180 to get 14x = 42

Divide 42 by 14 to get x = 3

Therefore x = 3