Question:
In the diagram below, $\overline{AB}\parallel \overline{CD}$ and $\angle AXE$ is $108^\circ$ less than 3 times $\angle CYX$.  Find $\angle BXY$.

[asy]

unitsize(1inch);

pair A,B,C,D,X,Y,EE,F;

A = (0,0);

B=(1,0);

C = (0,0.8);

D=(1,0.8);

EE = (0.35,-0.3);

F = (0.8,1.1);

draw(EE--F);

draw(A--B);

draw(C--D);

dot(A);

dot(B);

dot(C);

dot(D);

dot(EE);

dot(F);

label("$E$",EE,S);

label("$F$",F,N);

X = intersectionpoint(A--B,EE--F);

Y = intersectionpoint(C--D,EE--F);

label("$X$",X,NNW);

label("$Y$",Y,NNW);

label("$A$",A,W);

label("$B$",B,E);

label("$C$",C,W);

label("$D$",D,E);

dot(X);

dot(Y);

[/asy]

Answer:
Since $\overline{AB}\parallel\overline{CD}$, we have $\angle AXE = \angle CYX$.  Letting $x = \angle AXE$, we have $x = 3x - 108^\circ$.  Solving this equation gives $x = 54^\circ$.  We therefore have $\angle BXY = \angle AXE = \boxed{54^\circ}$.