Sagot :
25x²-4=(5x)²-2²=(5x-2)(5x+2)
A=25x²-4+(2x+3)(5x+2)
A=(5x-2)(5x+2)+(2x+3)(5x+2)
A=(5x+2)(5x-2+2x+3)
A=(5x+2)(7x+1)
b)
x²-14x+49=(x-7)²
B= (3x-4)(x-7)+(x²-14x+49)
B=(3x-4)(x-7)+(x-7)²
B=(x-7)(3x-4+x-7)
B=(x-7)(4x-11)
c)
A=0
(5x+2)(7x+1)=0
5x+2=0
5x=-2
x=-2/5
7x+1=0
x=-1/7
B=0
(x-7)(4x-11)=0
x-7=0
x=7
4x-11=0
4x=11
x=11/4
A=25x²-4+(2x+3)(5x+2)
A=(5x-2)(5x+2)+(2x+3)(5x+2)
A=(5x+2)(5x-2+2x+3)
A=(5x+2)(7x+1)
b)
x²-14x+49=(x-7)²
B= (3x-4)(x-7)+(x²-14x+49)
B=(3x-4)(x-7)+(x-7)²
B=(x-7)(3x-4+x-7)
B=(x-7)(4x-11)
c)
A=0
(5x+2)(7x+1)=0
5x+2=0
5x=-2
x=-2/5
7x+1=0
x=-1/7
B=0
(x-7)(4x-11)=0
x-7=0
x=7
4x-11=0
4x=11
x=11/4
a) Factorisation 25x² +4+(2x+3)(5x+2)
(5x-2)(5x+2) + (2x+3)(5x +2)
(5x+2) (5x-2 +2x+3)
(5x+2)(7x +1)
x² -14x +49 = (x-7)(x-7)
B = (3x-4)(x-7)+(x² -14x+49)
(3x-4)(x-7)+(x-7)(x-7)
(x-7)(3x-4 +x-7)
(x-7) (4x -11)
Equations
25x²-4+(2x+3)(5x+2) = 0
(5x-2)(5x+2) + (2x+3)(5x+2)=0
Si A = 0 cette équation n'a pas de solution.
(5x-2)(5x+2) + (2x+3)(5x +2)
(5x+2) (5x-2 +2x+3)
(5x+2)(7x +1)
x² -14x +49 = (x-7)(x-7)
B = (3x-4)(x-7)+(x² -14x+49)
(3x-4)(x-7)+(x-7)(x-7)
(x-7)(3x-4 +x-7)
(x-7) (4x -11)
Equations
25x²-4+(2x+3)(5x+2) = 0
(5x-2)(5x+2) + (2x+3)(5x+2)=0
Si A = 0 cette équation n'a pas de solution.