Bonjour,
A = ( -8+12-5+7 ) ( 11-13-7-2)
A= 6* -11
A= -66
B= -7*3 - 9*-5 + (-4) *9 - 7
B= -21 - (-45) -36 -7
B= -21 +45 -36-7
B= 24-36-7
B= -12-7
B= -19
C= 6 - ( -4 *-3 + 5* -2 ) * -4
C = 6 - ( 12 -10 ) * -4
C = 6 - ( -48 +40)
C= 6 - ( -8)
C = 6 +8
C = 14