DÉFI 1
© Guérin, éditeur ltée
2. a) a + b = b + a _________________________________________________________________________________________________________________________________________________________________________________________________
b) a − b = b − a __________________________________________________________________________________________________________________________________________________________________________________________________
c) a × b = b × a __________________________________________________________________________________________________________________________________________________________________________________________________
d) a ÷ b = b ÷ a __________________________________________________________________________________________________________________________________________________________________________________________________
3. a) (a + b) + c = a + (b + c) _______________________________________________________________________________________________________________________________________________________________________
b) (a − b) − c = a − (b − c) ________________________________________________________________________________________________________________________________________________________________________
c) (a × b) × c = a × (b × c) ________________________________________________________________________________________________________________________________________________________________________
d) (a ÷ b) ÷ c = a ÷ (b ÷ c) ________________________________________________________________________________________________________________________________________________________________________
4. a) a + 0 = 0 + a = a _______________________________________________________________________________________________________________________________________________________________________________________
b) a × 1 = 1 × a = a _______________________________________________________________________________________________________________________________________________________________________________________
c) a × 0 = 0 × a = 0 _______________________________________________________________________________________________________________________________________________________________________________________