f(x+g(0)) = 4x+ 6
let g(0) = c
f(x+ c) = 4x + 6
implied f(x) = 4(x-c) + 6 = 4x + 6 - 4c,
f(g(y)) = 3y+ 6 = 4g(y) + 6 - 4c, so g(y) = (3/4)y + c
Indeed f(x+ g(y)) = 4x+ 3y + 6
f(2011) = 8050 - 4c
2011+ f(2011) = 10061 - 4c
g(2011 + f(2011)) = (3/4)(10061 - 4c) + c , which is arbitrary...