Bonjour,
----------------------------------------------------------------------------------------------------------------------
Exercice 1 :
a. 2 + (-5) = -3
b. (-5) + 15 = 10
c. (-8) + (-7) = -15
d. (-12) - 8 = -20
e. (10) - (-2) = 12
f. (-25) - (-5) = -20
Exercice 2 :
a. 4 - (-2) + (-8) - (+7) = -9
b. (-27) - (-35) - (-20) + 17 = 45
c. 3,1 + (-3,5) - (+7,8) - (+1,6) = -2,8
Exercice 3 :
R = (-3+9) - (4-11) - (-5-6)
R = -3+9-4+11+5+6
R = 24
S = -3+12-(13-8)-(3+8)
S = -3+12-13+8-3-8
S = -7
T = -3-[4-(3-9)]
T = -3-(4-3+9)
T = -13
Exercice 4 :
a. -7 + 3 = -4
b. -13 - 8 = -21
c. +45 -72 = -27
d. -2 + 7 - 13 = -8
e. +8-5+12-2 = 13
----------------------------------------------------------------------------------------------------------------------
Au plaisir d'avoir aidée :)
