(3x-1)(5x+7)=0
tu as deux solutions :
1) 3x-1=0
3x=1 x=1/3
2) 5x+7=0
5x=-7 x=-7/5
(6x-12)(3x+9)=0
6x-12=0 3x+9=0
6x=12 3x=-9
x=2 x=-3
(2x-8)(5x+3)
2x-8=0 5x+3=0
2x=8 5x=-3
x=4 x=-3/5
(5-4x)(2x+7)=0
5-4x=0 2x+7=0
-4x=-5 2x=-7
x=5/4 x=-7/2
(3a-5)²=0
3a-5=0
3a=5
a=5/3
36-9a²=0
(6-3a)(6+3a)=0
6-3a=0 6+3a=0
-3a=-6 3a=-6
a=2 a=-2
4a²+4a+1
(2a+1)²
2a+1=0
2a=-1
a=-1/2
9a²-12a+4=0
(3a-2)²=0
3a-2=0
3a=2
a=2/3