Lösungen

27² = ( 20 + 7 )² = 400 + 280 + 49 = 729

29² = ( 20 + 9 )² = 400 + 360 + 81 = 841 oder 29² = ( 30 - 1 )² = 900 - 60 + 1 = 841

37² = ( 30 + 7 )² = 900 + 420 + 49 = 1369

41² = ( 40 + 1 )² = 1600 + 80 + 1 = 1681

45² = ( 40 + 5 )² = 1600 + 420 + 25 = 2045