Sagot :

jpmorin3

bjr

a)

99 x 87 = (100 - 1) x 87 = 8700 - 87 = 8613

b)

102 x 35 = (100 + 2) x 35 = 3500 + 70 = 3570

c)

64 x 97 = 64 x (100 - 3) = 6400 - 64 x 3 = 6400 - 192 = 6208

d)

53 x 103 = 53 x (100 + 3) = 5300 + 53 x 3 = 5300 + 159 = 5459