bonjour
1) ( 3 x - 3 ) ( x + 4 ) = 0
soit 3 x - 3 = 0 ⇔ 3 x = 3 ⇔ x = 1
soit x + 4 = 0 ⇔ x = - 4
S ( 1 : - 4 )
2) - ( 4 x - 1 )² - 36 = 0
- ( 4 x - 1 - 6 ) ( 4 x - 1 + 6) = 0
- ( 4 x - 7) ( 4 x + 5 ) = 0
( - 4 x + 7 ) ( 4 x + 5 ) = 0
soit - 4 x + 7 = 0 ⇔ - 4 x = - 7 ⇔ x = 7/4
soit 4 x + 5 = 0 ⇔ 4 x = - 5 ⇔ x = - 5/4
S ( 7/4 : - 5/4 )
3 ) 25 x² + 5 x - x = 0
25 x² + 4 x = 0
x ( 25 x + 4 ) = 0
soit x = 0
soit 25 x + 4 = 0 ⇔ 25 x = - 4 ⇔ x = - 4/25
S ( 0 ; - 4/25 )