Bonjour,
A=49x²-1
(7x-1) (7x+1)
identité remarquable : (a-b) (a+b)
B=4x²-12
4( x² -3)
C=(x+2)²-25
(x+2 -5) (x+2+5) =
(x-3)(x+7)
D=(x+2)²-3x(x+2)
(x+2)( x+2 -3x) =
(x+2)( -2x+2)
[tex]\rule{6cm}{1mm}[/tex]
Factorisons :
[tex]A = 49{x}^{2} - 1[/tex]
[tex]A = {(7x)}^{2} - {1}^{2}[/tex]
[tex]\green{A = (7x - 1)(7x + 1)}[/tex]
[tex]B = 4{x}^{2} - 12[/tex]
[tex]\blue{B = 4({x}^{2} - 3)}[/tex]
[tex]C = {(x + 2)}^{2} - 25[/tex]
[tex]C = {(x + 2)}^{2} - {5}^{2}[/tex]
[tex]C = (x + 2 - 5)(x + 2 + 5)[/tex]
[tex]\green{C = (x - 3)(x + 7)}[/tex]
[tex]D = {(x + 2)}^{2} - 3x (x + 2)[/tex]
[tex]D = (x + 2)(x + 2 - 3x)[/tex]
[tex]D = (x + 2)(- 2x + 2)[/tex]
[tex]\green{D = -2(x - 1)(x + 2)}[/tex]
[tex]\rule{6cm}{1mm}[/tex]
