text: a) Let f(kx+l)+b = x^2-2x.\nThen (kx+l)^2+b = x^2-2x.\nThen k^2x^2 + 2klx + l^2+b = x^2-2x.\nThen k^2 = 1, 2kl = -2, and l^2+b = 0.\nSo k = 1 or k = -1.\nIf k = 1, then 2l = -2, so l = -1 and (-1)^2+b = 0 so b=-1.\nIf k = -1, then -2l = -2, so l = 1 and 1^2+b = 0 so b = -1.\n\nSo either k = 1, l = -1, and b = -1\nor k = -1, l = 1, and b = -1.\n\nb.  I'm not sure how to do that.