For which of the following does y(a)−y(b)=y(a−b) for all values of a and b? Select the correct option:
A) y(x)=x^2	B) y(x)=x/2	C) y(x)=x+5	D) y(x)=2x−1	E) y(x)=|x|
To solve this easiest way is just put the value and see that if it equals or not.   with option 1. y(a) = a^2 and y(b) = b^2   so L.H.S = a^2 - b^2   and R.H.S = (a-b)^2 ==&gt; a^2 + b^2 -2ab.   so L.H.S not equal to R.H.S   with option 2. y(a) = a/2 and y(b) = b/2   L.H.S = a/2 - b/2 ==&gt; 1/2(a-b)   R.H.S = (a-b)/2   so L.H.S = R.H.S which is the correct answer.   answer:y(x)=x/2
<result>B</result>
For which of the following does y(a)−y(b)=y(a−b) for all values of a and b?