Remember, all inside angles in a triangle add up to 180°
So:
3x+5x+7+x+2=180
Combine like terms
9x+9=180
Subtract 9 from both sides
180-9=171
9x=171
Divide by 9 on both sides
171/9=19
x=19
Plug it into all the angle measures.
Angle X: x+2, 9+2=11, Angle X=11°
Angle Y: 5x+7, 5(9)+7=52, Angle Y=52°
Angle Z: 3x, 3(9)=27, Angle Z=27°
