1.
4x + 1/3 = 1/2x+2
24x + 2 = 3x + 12
24x - 3x = + 12 - 2
21x=10
x=10/21
2.
(5x − 4)(−3x + 7) = 0
S= { 4/5; 7/3 }
3.
3x(x − 3)² = 0
S= { 0; 3 }
4.
(7x − 5)² = 16 /!\ 4² = 16 ==> par exemple : -4 x -4 ou 4 x 4
7x-5 = 4
7x=9
x=9/7
et
7x-5 = -4
7x=-4+5
7x=1
x=1/7
S={1/7; 9/7)
5.
10(x + 7)(x − 5) − 3x(x + 7) = 0
(x+7) ( 10 (x-5) - 3x) =0
(x+7) ( 10x-50 - 3x) =0
(x+7) ( 7x-50) =0
donc
x=-7
x=50/7
S={-7; 50/7}
