bonjour pouvez vous m'aidez pour mes deux exercices de maths s'il vous plaît? merci

Bonjour

N°51

A = -2 (3/4 +5/2) +3/2
A = -2(15/20 + 8/20) + 3/2
A = -2 ( 23/20) +3/2
A = - 46/20 +3/2
A = - 46/20 + 30/20 = - 16/20 = - 4/5 = 0.8

A = (-6/4 -4/5) +3/2
A = (- 30/20 - 16/20) +3/2
A = - 46/20 + 3/2 = -46/20 + 30/20 = - 4/5 = 0.8

B = 4 [(3/4 - (-1/2)] - ( 1/2 + -5/6)
B = 4 (3/4 + 2/4) - (3/6 - 5/6)
B = 4 ( 5/4) - (-2/6)
B = 20/4 + 2/6 = 60/12 + 4/12 = 64/12 = 5.3333 arrondi et troncature = 5.33

B = (12/4 +4/2) - (1/2 -5/6)
B = (12/4 + 8/4) - ( 3/6 -5/6)
B = 20/4 + 2/6 = 60/12 + 4/12 = 64/12

N°59

A = 1/3 -1/3 x 4/7
A = 1/3 - 4/21
A = 7/21 - 4/21 = 3/21 = 1/7

B = 6/5 : (1/15 -1/5)
B = 6/5 : (1/15 - 3/15)
B = 6/5 : -2/15
B = 6/5 x -15/2 = - 90/ 10 = -9