Réponse :
[tex]24 \times 99 = (25-1) \times (100-1)\\24 \times 99 = 25 \times 100 + 25 \times (-1) -1 \times 100 -1 \times (-1)\\24 \times 99 = 2500-25-100+1\\24 \times 99 = 2376[/tex]
[tex]33 \times 102 = (30+3) \times (100 + 2)\\33 \times 102 = 30 \times 100 + 30 \times 2 + 3 \times 100 + 3 \times 2\\33 \times 102 = 3000 + 60 + 300 + 6\\33 \times 102 = 3366[/tex]
[tex]15 \times 1001 = 15 \times (1000+1)\\15 \times 1001 = 15 \times 1000 + 15 \times 1\\15 \times 1001 = 15000 + 15\\15 \times 1001 = 15 015[/tex]
[tex]18 \times 750 + 18 \times 250 = 18 \times (750 + 250)\\18 \times 750 + 18 \times 250 = 18 \times 1000\\18 \times 750 + 18 \times 250 =18000\\[/tex]
Bonne soirée !
