Résoudre dans R les équations suivantes.
a) 5x²-6x=0
x ( 5 x - 6 ) = 0
x = 0 ou 6/5
b) (2x+1)(x+4)+(x+4)(3-5x) = 0
( x +4 ) ( 2 x + 1 + 3 - 5 x ) = 0
( x + 4 ) ( - 3 x + 4 ) = 0
x = - 4 ou x = 4/3
c) (x-7)(3x-5)-(9x-4)(x-7)=0
( x - 7 ) ( 3 x - 5 - 9 x + 4 ) = 0
( x - 7 ) ( - 6 x - 1 ) = 0
x = 7 ou x = - 1/6
d) 4x²+8x+4=0
( 2 x + 2 )² = 0
x = - 1
e) (4x-7)(9x+5)=(8x-3)(4x-7)
( 4 x - 7 ) ( 9 x +5 ) - ( 8 x - 3 ) ( 4 x - 7 ) = 0
( 4 x - 7 ) ( 9 x + 5 - 8 x + 3 ) = 0
( 4 x - 7 ) ( x + 8 ) = 0
x = 7/4 ou x = - 8
