Résoudre les équations suivantes : a) x + 12 = 25 b) x – 51 = -10 c) 6x = 42 d) -5x = 255 e) 2x + 6 = 0 f) -7 - 3x = 19 g) 12 - x = 3x h) 4 + 8x = 11 - 3x i) 9x

bonjour

a) x + 12 = 25

  x = 25 - 12

  x = 13

b) x - 51 = - 10

  x = - 10 + 51

 x = 41

c) 6x = 42

  x =[tex]\frac{42}{6}[/tex]

x = 7

d) - 5 x = 255

  x = [tex]\frac{255}{-5}[/tex]

  x= - 51

e) 2x + 6 = 0

 2x = -6

  x = [tex]\frac{-6}{2}[/tex]

 x = - 3

f) -7-3x = 19

 - 3x = 19 + 7

 - 3x = 26

   3x = - 26

   x = [tex]\frac{-26}{3}[/tex]

g) 12 - x = 3x

    -3x - x = - 12

     4x = 12

     x = [tex]\frac{12}{4}[/tex]

    x = 3

h) 4+8x = 11 - 3x

  8x + 3x = 11 - 4

  11x = 7

 x = [tex]\frac{7}{11}[/tex]

i ) 9 x - 2 = 8 - x

  9x + x = 8+2

 10 x = 10

x = 1

j) 12x + 22 = 6x + 30

 12x - 6x = 30 - 22

6x = 8

x = [tex]\frac{3}{4}[/tex]

x = 0 .75