Réponse:
3°) 2x -5 +6x = 2 -6x +6x
2x +6x +6x -6x = 2 +5
2x +6x = 2+5. On supprime -6x et +6x , car ils sont deux nombres opposés.
8x = 7
8x/8 = 7/8
x = 7/8
4°) 8x -5 = 2
8x = 2+5
8x = 7
8x/8 = 7/8
x = 7/8
-(2x +3) -x+2 = 2-(x+7)
-2x -3 -x +2 = 2 -x -7
-2x -x +x = 2 -7 +3 -2
-2x = -7 +3
-2x = -4
-2x/-2 = -4/-2
x = 2
3(x-2) -4x = 2(x-5) +10
3x -6 -4x = 2x -10 +10
3x -4x -2x = -10 +10 +6
-x -2x = 6
-3x = 6
-3x/-3 = 6/-3
x = -2
5x -(4x-1) = 2 -6(2x -1/3) -3x
5x -4x +1 = 2 -12x +6/3 -3x
5x -4x +12x +3x = 2 +2 -1
x +15x = 4 -1
16x = 3
16x/16 = 3/16
x = 3/16
8/3x -3 = -(7+x)
8/3x -3 = -7 -x
8/3x +x = -7 +3
8/3x +3/3x = -4
11/3x = -4
11/3x × 3/11 = -4 × 3/11
x = -12/11
3/x -2 = 7
3/x = 7 +2
3/x = 9
x/3 = 1/9
x/3 × 3 = 1/9 × 3
x = 3/9
x = 1/3
x-4/3 = 7x-2/-2
-2(x-4) / -2×3 = 3(7x-2) / -2×3. simplifier l'équation en utilisant le produit en croix.
-2(x-4) = 3(7x-2). simplifier les deux membres de l'équation par -2×3.
-2x +8 = 21x -6
-2x -21x = -6-8
-23x = -14
-23x/-23 = -14/-23
x = 14/23
2(x -1/7) -5/7 = 7(x -2/21) -6x-2/3
2x -2/7 -5/7 = 7x -14/21 -6x-2/3
2x -7x = -2/3 -2/3 +2/7 +5/7
-5x = -4/3 +7/7
-5x = -4/3 +1
-5x = -4/3 +3/3
-5x = -1/3
-5x × 1/-5 = -1/3 × 1/-5
x = -1/15
