In: Advanced Math
Question 1. Let F be an ordered field. For each of the following
statements, prove the statement or provide a counterexample.
(a) For all x,y,z,w ∈F, if x < y and xw < yz, then w <
z.
(b) If x,y,z,w ∈F, then |x + w|≤|x + y|+|y + z|+|z + w|
Let x ∈R, a ∈R, and b ∈R.
(a) Suppose that |x−a| = 3|x−b|. Let
c =(9b−a)/ 8
. Prove that |x−c| = 3 8|a−b|