For any non-zero a and b that satisfy |ab| = -ab and |a| = -a, |b-4| + |ab-b| =	Choose the correct answer:  A) ab-4  B) 2b-ab-4  C) ab+4  D) ab-2b+4  E) 4-ab
Given: |ab| = -ab and |a| = -a   Question: |b-4| + |ab-b| = ?   **** Looking at |ab| = -ab tells us that either one of a or b is negative.   **** Looking at |a| = -a tells us that a must be negative   **** Combine two observations: b is positive   Let a=-1 and b=1   |b-4| + |ab-b| = |1-4| + |-1-1| = 5   Test a) |ab-4| = |(1)(-1)-4| = |-5|=5   Test b) 2b-ab-4 = (2)(1) - (-1) - 4 = -1   Test c) ab+4 = -1 + 4= 
<gadget id="calculator">-1 + 4</gadget>
<output>3</output>
3   Test d) ab-2b+4= -1-2(1)+4=1   test e) 4-1=3   ab-4NSWER=ab-4
<result>A</result>
For any non-zero a and b that satisfy |ab| = -ab and |a| = -a, |b-4| + |ab-b| =