bonjour,
il te faut reconnaitre les ir, factoriser puis résoudre = 0
a) (5x+1)² =0
5x+1 =0
5x = -1
x = -1/5
b)(3x-2)² = 0
3x-2 =0
3x = 2
x =2/3
c) 4x²-1 =0
(2x-1)(2x+1) = 0
x = -1/2; 1/2
d) 9x²-6x+1 =(3x-1)² = 0
3x =1
x =1/3
e) x²-7 = 0
(x-√7)(x+√7) = 0
x =-√7;√7
f) x²+3 =impossible
g) 4x²-3 = 0
(2x-√3)(2x+√3) = 0
2x-√3 =0
2x =√3
x =√3/2
2x+√3 =0
2x =-√3
x =-√3/2
h) (x-2)(2x-1+3x+4) = 0
(x-2)(5x+3) = 0
x-2 =0
x =2
5x+3 =0
5x =-3
x =-3/5
i) 25-(4x-1)² = 0
(5-4x+1)(5+4x-1) =0
(-4x+6)(4x+4) = 0
-4x+6 =0
-4x =-6
x =6/4 =3/2
4x+4 =0
4x =-4
x =-1
j) (3x-9)²-1 = 0
(3x-9-1)(3x-9+1) = 0
(3x-10)(3x-8) = 0
3x-10 =0
3x =10
x =10/3
3x-8 = 0
3x =8
x =8/3
k) (2x-1)(2x-1-x+5) = 0
(2x-1)(x+4) = 0
2x-1 =0
2x = 1
x =1/2
x+4 =0
x =-4
i)(x-2)²-16 =0
(x-2-4)(x-2+4) =0
(x-6)(x+2) = 0
x= 6; -2
