Réponses

2013-09-22T19:25:07+02:00
a) 7 ( x - 2 ) + 4 ( x + 3 ) = 0
7x -14 +4x +12 = 0
7x +4x = - 12+14
11x= 2
x = 2/11

b) 3 ( x - 4 ) = 7 ( 2x - 1 )
3x-12 = 14x-7
3x-14x = -7 +12
-11x = 5
x = 5/11

c) 2 ( x - 3 ) + 3 ( x - 6 ) - 6 ( x + 4 ) = 0
2x-6 +3x-18 -6x-24 = 0
2x +3x -6x = 24 +18 +6
-x = 48
x = -48
d) ( x + 1 ) ( x - 2 ) - x² + 3 = 0
x² -2x+x-2 - x² +3 = 0
-x = -3+2
-x = -1
x = 1