résoudre les equation suivantes 8x = 12x +4 7x - ( 5x + 3 ) = 5 ( x - 3 ) + 2 7x + 1 = - 1 - x 5x/8 - 3/10 = 7x/40 A = 3 ( 2w -6) - ( 3 - 5x ) B = ( 2a - 5 ) (

8x-12x=4
-4x=4
4x/4 = 4/4
x = 1

8x = 12x +4
8x -12x = +4
-4x = 4
x = 4/4
x=1
7x -(5x+3) = 5(x-3)+2
7x -5x -3 = 5x -15 +2
7x -5x -5x = +3 -15 +2
-3x = -10
x = -10/3
7x +1 = -1 -x
7x +x = -1 -1
8x = -2
x = -2/8 = -1/4
5x/8 -3/10 = 7x/40
5x/8 X10/10 -3/10 X 8/8 = 7x/40
50x/80 -24/80 = 7x/40
50x/80 -7x/40 = 24/80
50x/80 -14x/80 = 24/80
36x/80 = 24/80
18x/40 = 12/40
9x/20 = 6/20

A =  3 ( 2w -6) - ( 3 - 5x )
6w -18 -3 +5x
6w -21 +5x
B = ( 2a - 5 ) ( 3 - 4a ) - 2 ( 5 - a )
6a -8a² -15 +20a -10 + 2a
28a -8a² -25