Chapitre 5 Equations et équations produit nul

7x+ 9 = 5x−2
x
−5x
7x−5x
×2x
5x−9 = 6x−2
x
−6x
5x−6x
×(−1) x
2
3x−4 5= 6x+ 4
x
+4
5
−6x
2
3x−6x
×(−16
3)x−16 3
−3
16

3n+ 3 = 1266
A×B×C= 0
(3x+ 9)(5x−1)(x+ 7) = 0

x2=a
x2= 9
(x−3)(x+ 3) = 0
a x2=a
a
a
f(x) = x2
x2=−2
x2= 15
x2= 25