The G.M. of numbers 4, 5, 10, 20, 25 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)