bonjour,
4x²-12x+9 = a²-2ab+b² =(a-b)² = (2x-3)²
(5x+3)²-(3x-4)² = a²-b² = (a-b)(a+b)=
(5x+3-3x+4)(5x+3+3x-4) =
(2x+7)(8x-1)
équation
(2x-7)(4x+8)=0
2x-7 = 0
2x =-7
x =7/2
4x=8 =0
4x =-8
x =-2
9x²+12x+4=0
(3x+2)² = 0
3x= -2
x =-2/3
(5x+3)² = (5x+3)(3x-1)
(5x+3)²- (5x+3)(3x-1) = 0
on facto :
(5x+3)(5x+3-3x+1) =0
(5x+3)(2x+4) = 0
5x+3 =0
5x = -3
x =-3/5
2x+4 =0
2x =-4
x =-4/2 =-2