p(-3), namely what is p(x) when x = -3 well, let's take a peek at the ranges in the subfunctions.
-8 ⩽ x < -3 , in this case "x" is less than -3 and greater than -8, however is not -3.
-3 < x ⩽ 3 , in this case "x" is greater than -3, however is not -3 itself
so x = -3 doesn't exist in the range for the piece-wise function.
p(4), when x = 4, that's in the range of 3 < x < 8, and the subfunction will be (x-5)² - 5, thus
( 4 - 5)² - 5
(-1)² - 5
6.