bonjour, est ce que quelqu'un pourrait m'aider pour cet exercice svp?

A = 99x87
A = (100-1)x(90-3)
A = 100x90 + 100*(-3) + (-1)x90 + (-1)x(-3)
A = 9 000 - 300 - 90 + 3
A = 8 700 - 90 + 3
A = 8 610 + 3
A = 8 613

B = 102x35
B = 35x102
B = 35x(100 + 2)
B = 35x100 + 35x2
B = 3 500 + 70
B = 3 570

C = 64x97
C = (60 + 4)(100 - 3)
C = 60x100 + 60x(-3) + 4x100 + 4x(-3)
C = 6 000 - 180 + 400 - 12
C = 5 820 + 400 - 12
C = 6 220 - 12
C = 6 208

D = 53x103
D = (50 + 3)(100 + 3)
D = 50x100 + 50x3 + 3x100 + 3x3
D = 5 000 + 150 + 300 + 9
D = 5 150 + 300 + 9
D = 5 450 + 9
D = 5 459