Hello,
Let me try out the solution for you.
Consider the below scenarios for the equation y = |x+5|-|x-5|
Case 1:
when x more than or equal to 5
then y=(x+5)-(x-5) = 10
hence y=10
Case 2:
when -5<x<5
y=(x+5)-(-(x-5)) = 2x
y=2x so y can take 9 values corresponding to x={-4,-3,-2,-1,0,1,2,3,4}
Case 3:
when x less than or equal to -5
y= -(x+5)-(-(x-5))
y=-10
Hence if we combine all 3 cases we get that y can take total of 11 values.