Sagot :
Bonjour,
101 × 54 = (100 + 1) × 54 = 100 × 54 + 1 × 54 = 5 400 + 54 = 5 454
de la même façon :
99 × 87 = (100 - 1) × 87 = 100 × 87 - 1 × 87 = 8 700 - 87 = 8 613
102 × 35 = (100 + 2) ×35 = 100 × 35 + 2 × 35 = 3 500 + 70 = 3 570
64 × 97 = 64 × (100 - 3) = 64 × 100 - 64 × 3 = 6 400 - 192 = 6 208
je te laisse faire le dernier sachant que 103 = 100 + 3
Bonjour,
Exercice 42:
il utilise la distributivité:
54 * 100 + 1*54 = 5 400 +54 = 5 454
Exercice 43
(100-1) * 87 = 8 700 -87 = 8 613
(100 +2) *35= 3 500 +70 = 3 570
(100 -3) * 60 +(100 -3) * 4 =
6000 -180 + 400 -12 =
6 400 -100 -80 -12 =6 208
(100 +3) *50 + (100+3)*3 =
5 000 +150 + 300 +9=
9 450 + 9 = 5 459