kill(all)$

van=facebook.com/LearningCalculus$

f(x):=2^(1-x);

g(x):=x+5;

f(-1);

g(-1);

f(x)=g(x);

f(-1)=g(-1);

solve(%,x);

x=(W(64*log(2))-5*log(2))/log(2);