Réponse :
Explications étape par étape
A = ( - 3 ) * ( - 1 ) * ( + 5 ) * ( - 8 )
(-3)*(-1) = 3
(+5)*(-8) = -40
3*(-40) = -120
B = ( - 3 ) * ( - 2 ) * ( + 12 ) * ( - 5 ) * ( - 1 )
(-3)*(-2) = 6
(-5)*(-1) = 5
12*5 = 60
60*6 = 360
C = ( + 7 ) * ( - 1 ) * ( +3 ) * ( - 2 ) * ( + 1 )
(+7)*(-1) = -7
(-2)*(+1) = -2
(3)*(-2) = -6
(-7)*(-6) = 42