4. Let I = {he Q[x] | h(3) = h(5) = 0}, an ideal of Q[x]. (a) Find non-zero elements f + / and g+/ of Q[x]// such that (f+D)(g+1) is equal to the zero element of Q x]/I. Justify your answer. Make sure you explain, if only very briefly, why neither f nor g is in I. (b) Now instead let f = r and g = - (c -8), elements of Q r]. We know that f is not a unit of Q[x], but show that f + I is a unit of Q[x]/I by showing that (f + D)(g + [) =1+ 1