bonsoir

84 = 2 ² x 3 x 7

128 = 2 ⁷

donc PGCD = 4

tu simplifies par 4

56/24 x 36/49 = 12/7

A = 7/5 - 7/5 : ( 3/2 + 2 )

= 7/5 - 7/5 : ( 3/2 + 4/2 )

= 7/5 - 7/5 : 5/2

= 7/5 - 7/5 x 2 /5

= 7/5 - 14 /25

= 35/25 - 14 /25

= 21/25

B = - 3 + 3 ² x 5 - ( - 6 ) - 2 ³ x 6

= - 3 + 45 + 6 - 8 x 6

= - 3 + 51 - 48

= 0

A ≠ B

6 x 10 ¹² x 35 x 10 ⁻⁴ : 14 x 10 ³

= 210 x 10 ⁸ : 14 x 10 ³

= 15 x 10 ⁵

= 1.5 x 10 ⁶