Bonsoir,
(3y-5) (6y+7)
= 18y² +21y -30y -35
= 18y² -9y -35
(5y-6) (7y-2)
= 35y² -10y -42y +12
= 35y² -52y +12
Réponse:
Tu dois juste développer ...
(3y-5) (6y+7) = 18y² + 21y -30y -35 = -9y -35 +18y²
(5y-6) (7y-2) = 35y² -10y -42y +12 = 35y² -52y +12