Mathématiques

Question

Résoudre dans R les équations suivantes:
a. [tex]( x+1)^{2} [/tex] = -1
b. [tex]( 4x-8)^{2}= (3x+1)^{2} [/tex]
c.[tex] (-x+2)^{2} [/tex]= 169
e.[tex] x^{2} [/tex]-1=(x+1)

1 Réponse

  • a. = -1
    (x+1)² -1 =0
    (x+1-1)(x+1+1) =0
    x(x+2) =0

    x = 0                 ou x+2 =0
                                  x = -2

    b.
    (4x-8)²-(3x+1)² =0
    (4x-8-3x-1)(4x-8+3x+1) =0
    (x-9)(7x-7) =0

    x-9 =0                    7x-7 =0
    x = 9                            7x = 7
                                         x = 7/7 =1

    c.= 169
    (-x+2)² -169 =0
    (-x+2)² -13² =0
    (-x+2-13)(-x+2+13) =0
    (-x-11)(-x+15) =0

    -x-11 =0                 -x+15 =0
    -x = 11                     -x =-15
    x = -11                      x =15

    e.-1=(x+1)
    (x-1)(x+1) -(x+1) =0
    (x+1)(x-1-1) =0
    (x+1)(x-2) =0

    x+1 =0              x-2 =0
    x = -1               x = 2

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