Answer:
Step-by-step explanation:
LET:
∠XYW=Y
X,Y and W are the angles of triangle so:
X + Y + W=180
3x+11+Y+5x+1=180
Y=180-12-8x
Y=168-8x
Now ∠XYW and ∠XYZ are the angles of a straight line:
∠XYW+∠XYZ=180
168-8x+12x-20=180
4x+148=180
4x=180-148
4x=32
x=32/4
x=8
Now substitute value of x in Y:
∠(12x-20)=12(8)-20
∠Y=76
