Bonjour,
a) Développer l’expression
(5g-6)²+(g+4)(5g-6)
= 25g² - 80g + 36 + 5g² - 6g + 20g - 24
= 25g² + 5g² - 80g - 6g + 20g + 36 - 24
= 30g² - 66g + 15.
b) Factoriser
(5g-6)²+(g+4)(5g-6)
= (5g - 6) (5g - 6 + g + 4)
= (5g - 6) (6g - 2).
= 2 (3g - 1) (5g - 6)
