Réponse:
A=(-5)x(-6):(+3)+(-2)x(+4)
= 30/3 - 8
= 10 - 8
= 2
B=(-5)+(-2)+(+3)+(-1)+(+4)
= -5 - 2 + 3 - 1 + 4
= -1
C=40-(7-6x2)
= 40 - (7-12)
= 40 + 5
= 45
D=-2x4+6x(-5)
= -8 - 30
= -38
E=2-2x5
= 2-10
= -8
F=[30-(3+7x2)]-[28-(-20+2x4)]
= [30-(3+14)]-[28-(-20+8)]
= [30-17]-[28-(-12)]
= [13]-[28+12]
= [13]-[40]
= -27