Réponses

2013-11-17T15:04:51+01:00
3x+5=6x-7
3x-6x=-7-5
-3x=-12
x=12/3
x=4

6x+3=2x-4
6x-2x=-4-3
4x=-7
x=-7/4

5(x+2)=6(2x-7)
5x+10=12x-42
5x-12x=-42-10
-7x=-52
x=52/7

-3(3-x)=4(3x-6)
-9+3x=12x-24
3x-12x=-24+9
-9x=-15x
x=15/9
x=5/3

4x(x-2)=4x²+6x-8
4x²-8x=4x²+6x-8
4x²-4x²-8x-6x=-8
-14x=-8
x=8/14
x=4/7

(5x+2)(4x-3)=20x²-6x+40
20x²-15x+8x-6=20x²-6x+40
20x²-20x²-15x+8x+6x=40+6
-x=46
x=-46

(4-3x)(5x+8)=38-15x²
20x+32-15x²-24x=38-15x²
20x-15x²-24x+15x²=38-32
-4x=6
x=-6/4
x=-3/2