Answer:
C
Step-by-step explanation:
Using the given definition
x δ y = [tex]\frac{x+y}{x-y}[/tex] , then
a δ (a - b)
= [tex]\frac{a+a-b}{a-(a-b)}[/tex]
= [tex]\frac{2a-b}{a-a+b}[/tex]
= [tex]\frac{2a-b}{b}[/tex] → C
