résoudre ces équations : ( trouvez la valeur de x) a. 4(2x - 1) = 7 b. -2x + 3 = -2(x - 5) C. -5(4 + 3x) = 2(- x + 1) d. - 4x – 10 = -5x - 1 e.

Réponse:

a ) 4 ( 2x -1 ) = 7

8x-4 = 7

8x = 7+4

8x = 3

x = 8 ÷ 3

b) -2x +3 = -2(x-5 )

-2x +3 = -2x +10

-2x +2x = 10-3

0= 7

C) -5(4 +3x) = 2( -x +1)

-20 -15x = -12x +2

-15x +12x = 20+2

-3x= 22

x = 22÷ 3

d) -4x - 10 =5x -1

-4x -5x = 10-1

- x= 9

x = -9