Réponses

2014-03-22T13:03:22+01:00
1) (5x+1)(8-x)=0
5x+1=0 ou 8-x=0
5x=-1 ou -x=-8
x=-1/5 ou x=8

2) 3x-1+7-x=0
2x+6=0
2x=-6
x=-6/2
x=-3

3) 8+3x+x+3=0
4x+11=0
4x=-11
x=-11/4

4) 3-10x=0 ou x+23=0
-10x=-3 ou x=23
x=3/10 ou x=23

5) 6y+18-2y+1=0
4y+19=0
y=-19/4
2014-03-22T13:06:48+01:00
1) (5x+1) (8-x)=0
   5x+1 = 0 ou 8-x = 0
  5x = -1  ou x = 8
  x = -1/5 ou x = 8

2) (3x-1)+(7-x)=0
    3x-1+7-x = 0
    2x+6=0
     2x=-6
     x=-6/2
     x = -3
3) (8+3x)+(x+3)=0
   8+3x+x+3 = 0
   4x+11 = 0
    4x = -11
     x = -11/4
4) (3-10x) (x+23) =0
    (3-10x) = 0 ou (x+23) = 0
     10x = 3    ou   x = -23
        x = 3/10 ou  x = -23

5) 6(y+3)-2(y-1)=0
   6y+18-2y+1 = 0
   4y +19 = 0
   4y = -19
     y = -19/4