The value of [(−4)×(−9)×(−25)]÷[(−2)×(−3)×(−5)] is __________?
Subtract without using number line:
(1) 40 from 50
(2) −20 from + 30
(3) −25 from −40
(4) +20 from −50
(5) +25 from −25
(6) −25 from + 25
(7) +40 − (−10) − (+20)