Find the solution to each number sentence below:

(1) - 10 + 15 = _______

(2) 28 + (-29) = _______

(3) -40.5 + (-0.5) = ______

(4) 50 - (- 5) = ______ (5) 100 - 255 = ______
(Hint: take away a negative means adding the opposite)