For any a and b that satisfy |a – b| = b – a and a > 0, then |a + 4| + |-b| + |b – a| + |ab| = Select.
A) a-b+4	B) ab-b+4	C) ab + 2b + 4	D) 2ab+b+2	E) ab+2b+2
Observation-1: |a – b| = b – a   which is possible only when signs of a and b are Same   Since Given a &gt; 0   so we figure out that a and b are both positive   Observation-2: |a – b| must be Non-Negative and so should be the value of b-a which is possible only when absolute value of b is greater than or equal to absolute value of a   Now you may choose the values of a and b based on above observations   e.g. b = 4 and a=1 and check the value of given functions and options   |a + 4| + |-b| + |b – a| + |ab| = |1 + 4| + |-4| + |4 – 1| + |1*4| = 16   ab + 2b + 4= 1*4+8+4= 
<gadget id="calculator">1*4+8+4</gadget>
<output>16</output>
16   all other options are not equal to 16   Answer : ab + 2b + 4
<result>C</result>
For any a and b that satisfy |a – b| = b – a and a > 0, then |a + 4| + |-b| + |b – a| + |ab| =