Idempotent elements in a ring

Let R be a commutative ring with 1 and suppose eR is idempotent, i.e., satisfies e2=e.

  1. Prove that 1e is also idempotent.
  2. Suppose e0,1. Show that Re and R(1e) are proper ideals of R.
  3. Prove there is an isomorphism RRe×R(1e).