bonjour j ai un devoir en maths je n y arrive pas merci

Réponse :

Explications étape par étape

A= (-2/7 + 5/42) x (5 - 3/8)

= (-12/42 + 5/42) x (40/8 - 3/8)

= (-7/42) x (37/8)

= (-259/336)

= (-259/336) / 7 = -37/48

B= (2/5 + -3/4) / 2+(-2) x -7/4

= (8/20 + -15/20) / 2 + 14/4

= (-7/20) / 2+7/2

= (-7/20) / 4/2 + 7/2

= (-7/20) / 11/2

= -7/20 x 2/11

= -14/220

= (-14/220) / 2

= -7/110

C= 8/7 - (-4/7) x 5/3

= 8/7 - (-20/21)

= 24/21 + 20/21

= 44/21

D= -3/ 2+5/2

= -3/ 4/2+5/2

= -3/ 9/2

= -3 x 2/9

= -6/9

= (-6/9)/3

= -2/3

E= ( -2/3 - (-4/9) ) + (5/2 + 1/2 x 3/-7)

= ( -6/9 - (-4/9) ) + (5/2 + 3/-14)

= (-2/9) + (-35/-14 + 3/-14)

= (-2/9) + (-32/-14)

= -2/9 + 32/14

= -28/126 + 288/126

= 260/126

= (260/126)/2

= 130/63