I think i got it but i just want clarification

To simplify an expression you have to subtract the lower exponent from the higher one, therefore Regan is correct.

answer: expected value of x = 1.0

step-by-step explanation:

p(x=0) = 0.25

p(x=1) = 0.50

p(x=2) = 0.25

expected value for x = 0×0.25 + 1×0.5 + 2×0.25 = 1.0

in simplified version   it would be x ≤-4

step-by-step explanation:

multiply each term in x ≤-4 by -1