bjr

3

360 = 2 x 180

       = 2 x 2 x 90

       = 2 x 2 x 2 x 45

       = 2³ x 5 x 9

       = 2³ x 3² x 5

111    = 3 x 37

A = 12/5 - 3/5 x 7/9

priorité à la multiplication

A = 12/5 - (3x7 / 5x9) = 12/5 - (3x7 / 5x3x3) = 12/5 - 7/15

on met sous un même dénominateur

A = 36/15 - 7/15 = 29/15

B = (1/7 - 2) x 14/45

priorité au calcul dans la (   )

B = (1/7 - 14/7) x 14/45 = -13/7 x 14/45 = -13x14/7x45 = -13x7x2/7x45

B = -26/45

C = 3/4 : 9/8 + 6 x (5/9 - 1)²

C = 3/4 x 8/9 + 6 x (-4/9)²

C = 3x8/4x9 + 6 x (16/81)

C = 3x4x2/4x3x3 + (6x16) / 81

C = 2/3 + 3x2x16/3x27

C = 2/3 + 32/27 = 18/27 + 32/27 = 50/27

D = 99/100 x 14/27 x 25/22

D = (99x14x25) / 100x27x22

D = 9x11x7x2x5x5 / 5x20x3x3x3x11x2

D = 7x5/5x4x3 = 7/12

3) 2 x 10¹⁵ va terminer par un zéro + 7 = nombre impair